Abstract

INTRODUCTION

Nitschke (1867) erected the pyrenomycete genus Anthostoma based on A. decipiens (DC.) Nitschke, basionym Sphaeria decipiens DC. In the same work he also recognised Anthostoma subg. Lopadostoma Nitschke, which later Traverso (1906) elevated to generic rank. Nitschke had only included Lopadostoma turgidum in his subgenus. This species is therefore the type of the genus, contrary to Clements & Shear (1931) and von Arx & Müller (1954), who listed L. gastrinum as the type species of Lopadostoma. Læssøe (1994) accepted Lopadostoma in the Xylariaceae, as had been already concluded by Haynes (1969), based on a developmental study on ‘L. gastrinum’ from Quercus. Martin (1969) keyed out 16 species of Lopadostoma, combined 13 of them invalidly, either by neglecting an earlier combination (L. juglandinum), by omitting the basionym or stating it as a synonym, but later he (Martin 1976) provided the basionym for 11 species and a validating diagnosis including type information for L. stictoides. Rappaz (1992, 1993) studied the sexual and asexual morphs of Anthostoma decipiens and concluded that the fungus belongs to the Diatrypaceae as a distinct genus close to Eutypella. Lu & Hyde (2000) accepted Rappaz’ view. Earlier Læssøe & Spooner (1994) had combined A. decipiens in Cryptosphaeria Ces. & De Not.

Rappaz (1995) listed only L. turgidum and L. gastrinum in his Lopadostoma subg. Lopadostoma, widened the concept of the genus and erected Lopadostoma subg. Anthostomopsis for species with similar asci and ascospores but differing in perithecia that are immersed in eutypoid configuration in wood. In addition, he established Barrmaelia for species similar to this subgenus, but with inamyloid ascus apices and ascospores that tend to be allantoid, i.e. being closer to the Diatrypaceae.

Læssøe & Spooner (1994), Rappaz (1995) and Lu & Hyde (2000) provided keys to genera including Anthostoma, Anthostomella and Lopadostoma and others that are similar to them. The genus Anthostomella differs from Lopadostoma in that the perithecia are solitary, scattered or variously aggregated, that stromatic tissues are confined to a clypeus and that the mostly ellipsoid ascospores often have a dwarf cell, i.e. a small hyaline cellular appendage at one end. Furthermore, species of Anthostomella only rarely occur in branches of trees. Lopadostoma in a strict sense occurs always in bark of trees or shrubs with perithecia immersed in pustulate pseudostromata, referred to as stromata below; its ascospores are more or less oblong, small, never with a dwarf cell. Within so-called ‘stromatic’ genera closest to Lopadostoma are Helicogermslita and Leptomassaria, which differ by spiralling ascospore germ slits, Helicogermslita also by the absence of an apical apparatus. Barrmaelia differs mostly by inamyloid ascus apices, effused stromata and pale brown ascospores tending to be allantoid. Below we revise several species, establish new ones and also show that Lopadostoma subg. Anthostomopsis is generically different from Lopadostoma s.str.

MATERIALS AND METHODS

Analysis of sequence data

To reveal the phylogenetic position of Lopadostoma within the Xylariaceae and to investigate whether the genus is monophyletic, a phylogenetic analysis was performed with nuLSU rDNA (LSU) sequences. Sequences of representative species of Xylariaceae and Diatrypaceae were selected from GenBank; Hypocrea rufa and Nectria cinnabarina (Hypocreales) were included as outgroup taxa. GenBank accession numbers are given in the phylogenetic tree (Fig. 1). For detailed investigations of species relationships and delimitation within Lopadostoma, a combined matrix of nuSSU-ITS1-5.8S-ITS2-LSU rDNA and rpb2 sequences was produced for phylogenetic analyses, with Lopadostoma pouzarii as outgroup according to Fig. 1. The GenBank accession numbers of sequences used in these analyses are given in Table 1.

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Fig. 1

Phylogram showing one of eight MP trees 950 steps long revealed by PAUP from an analysis of the nuLSU matrix of selected Xylariaceae and Diatrypaceae, showing the phylogenetic position of Lopadostoma spp., Barrmaelia macrospora, Anthostoma decipiens and Cryptovalsa rabenhorstii. MP and ML bootstrap support above 50 % are given at the first and second position, respectively, above or below the branches. Nodes collapsed in the strict consensus of the eight MP trees are marked by asterisks (*). GenBank accession numbers are given following the taxon names; species sequenced in the present study are formatted in bold. Species labelled in red correspond to Lopadostoma s.str.; species labelled in blue are not congeneric with Lopadostoma.

Sequence alignments for phylogenetic analyses were produced with either MUSCLE v. 3.6 (Edgar 2004) or MAFFT 6.847 (Katoh et al. 2002, Katoh & Toh 2008) implemented in UGENE 1.10.0 (http://ugene.unipro.ru). The resulting alignments were checked using BioEdit v. 7.0.9.0 (Hall 1999). After the exclusion of excessive leading and trailing gap regions and of ambiguously aligned positions, the LSU matrix contained 1 340 characters. The combined data matrix contained 3 342 characters; viz. 2 198 nucleotides of nuSSU-ITS-LSU and 1 144 nucleotides of rpb2.

Maximum parsimony (MP) analyses of the nuLSU matrix were performed with PAUP v. 4.0 b10 (Swofford 2002), using 1 000 replicates of heuristic search with random addition of sequences and subsequent TBR branch swapping (MULTREES option in effect, COLLAPSE=MAXBRLEN, steepest descent option not in effect). All molecular characters were unordered and given equal weight; analyses were performed with gaps treated as missing data. Bootstrap analysis with 1 000 replicates was performed in the same way, but using 10 rounds of random sequence addition and subsequent TBR branch swapping during each bootstrap replicate; each bootstrap replicate was limited to 1 million rearrangements. The combined matrix was analysed with the same settings, except that COLLAPSE=MINBRLEN was implemented.

For ML analyses of both matrices, 1 000 fast bootstrap replicates were computed with RAxML (Stamatakis 2006) as implemented in raxmlGUI 0.95 (Silvestro & Michalak 2012) using the GTRCATI substitution model. Model parameters were calculated separately for the two different gene regions included in the combined analyses.

RESULTS

Phylogeny

Of the 1 340 characters in the LSU alignment, 238 were parsimony informative. Fig. 1 shows one of eight MP trees of 950 steps. Tree topology of all eight MP trees was identical except for three minor differences; the three nodes collapsed in the strict consensus tree of the eight MP trees are marked by asterisks in Fig. 1. MP and ML bootstrap support above 50 % are given in Fig. 1 at the first and second position, respectively, above or below the branches.

Of the 3 342 characters in the combined data matrix, 568 were parsimony informative. Fig. 2 shows one of 29 MP trees of 1 552 steps. Tree backbone of all MP trees was identical and topologies differed only within species. MP and ML bootstrap support above 55 % are given in Fig. 2 at the first and second position, respectively, above or below the branches.

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Fig. 2

Phylogram showing one of 29 MP trees 1 552 steps long revealed by PAUP from an analysis of the combined ITS-LSU-rpb2 matrix of Lopadostoma, with Lopadostoma pouzarii selected as outgroup. MP and ML bootstrap support above 55 % are given at the first and second position, respectively, above or below the branches. Strain/culture designations are given following the taxon names; holo-, neo- or epitype strains/specimens are formatted in bold. Colours refer to the hosts: red Quercus spp., dark blue Fagus sylvatica, orange Corylus avellana, olive Prunus padus, light green Ulmus spp., dark green Acer campestre, turquoise Carpinus betulus and lavender Pistacia lentiscus.

In most cases, ITS and rpb2 sequences were identical or nearly identical within the species, except for L. meridionale which showed unusually high intraspecific variation in both genes, which is reflected in long branches within that species (Fig. 2).

Molecular phylogenetic analyses of the nuLSU matrix confirmed monophyly of Lopadostoma s.str. with moderate support; sister group relationship to Creosphaeria sassafras, which has a similar asexual morph as Lopadostoma spp., receives low support. Nodes above this level have no statistical support, therefore conclusions about a relationship of the clade containing this group and the accessions of Lopadostoma cf. polynesium and Anthostomella cf. conorum cannot be drawn. Lopadostoma pouzarii, L. cf. amoenum, L. cf. polynesium and Barrmaelia macrospora are phylogenetically distinct from Lopadostoma s.str. and dispersed among Xylariaceae (Fig. 1). Anthostoma decipiens and Cryptovalsa rabenhorstii are placed within Diatrypaceae (Fig. 1).

Molecular phylogenetic analyses of the combined matrix revealed 10 distinct taxa within Lopadostoma (Fig. 2), which are recognised at the species level. Of these, Lopadostoma gastrinum and L. turgidum have already been validly combined; two lineages represent already described taxa, which require formal transfer to Lopadostoma (Phaeosperma dryophilum, Sphaeria linosperma); and six represent yet undescribed species (L. americanum, L. fagi, L. insulare, L. lechatii, L. meridionale and L. quercicola). All species were molecularly highly distinct and received high internal support (Fig. 2). The five Lopadostoma species growing on Quercus formed an unsupported (Fig. 1) and highly supported (Fig. 2) monophylum in the analyses of the nuLSU and the combined matrices, respectively. Lopadostoma gastrinum, L. lechatii and L. linospermum formed a highly supported clade in both analyses. Morphological characters, such as ascospore size and colour of the entostroma did not correlate with phylogenetic relationships, as e.g. L. dryophilum and L. linospermum, which are conspicuously similar in these characters, reside in different clades.

Phenotype

Lopadostoma in a strict sense, i.e. as a monophylum, is highly conserved in sexual and asexual morphology and therefore only two or few species have been recognised, mainly L. turgidum on Fagus with little morphological variation and L. gastrinum on various hosts, with more pronounced variation but no distinct character states that could be recognised as useful for distinction. Most species defined here have stromata that would have been recognised as L. gastrinum.

Sexual morphs

In Lopadostoma sexual morphs form pustulate or widely effused stromata, typically immersed in and erumpent from bark, standing on the wood, with only an ectostromatic disc visible or the disc surrounded by blackened bark surface that may be conceived as a clypeus or dorsal stromatic zone; less commonly stromata are superficial on wood after bark disintegration. The ectostromatic disc may be discrete or fused in long bands or lines, circular, elliptic or oblong in outline, even, convex or pulvinate, flush with the bark surface or raised, dark brown, grey or black, smooth or tubercular, with ostioles opening separately in the disc, the latter mostly inconspicuous and umbilicate, sometimes convex, shiny black, or distinctly projecting and cylindrical; varying within species, but with tendencies among species, e.g. ostioles never distinct in L. turgidum, usually papillate in L. dryophilum and L. quercicola, disc tubercular with more or less projecting ostioles in L. insulare. Stromata are subglobose to bluntly conical in shape, less commonly widely effused, flat-pulvinate, surrounded by a narrow, black, carbonised encasement, which delimits the stroma from wood and bark. This is seen as a black line in section and referred to it as such in the descriptions below. The entire fungal material encased by the black line is here defined as the stroma. Stroma tissues consist of bark cells mixed with pale-coloured fungal hyphae in lower parts, often appearing mottled, whitish to pale brown; upward, particularly between ostiolar necks the entostroma is often dark or characteristically coloured, e.g. yellow-brown to olivaceous (L. dryophilum, L. linospermum). The stromata may contain one to many groups of perithecia (part stromata). Perithecia are as a rule clustered in valsoid groups, mono-, di- or rarely polystichous, subglobose or flask-shaped and have a dark brown to black wall and short or long more or less convergent ostiolar necks. Paraphyses are numerous, long, apically free, 1.5–3.5(–5) μm wide, little branched. Asci are cylindrical, stipitate, with 8 more or less uniseriate ascospores and a globose to ellipsoid apical apparatus typically 4–4.5 μm wide, which contains a flat ring-like part blueing in iodine at its lower end, referred to as apical ring in descriptions; the size of the ring is proportional to the ascus size. Length and width of asci and oblique to biseriate arrangement of ascospores is much dependent on mount preparation, i.e. the pressure applied to separate asci. Ascospores are oblong to narrowly ellipsoid, less commonly broadly ellipsoid or banana-shaped, typically symmetrical to slightly inequilateral, unicellular, lack a dwarf cell, are first hyaline, turn pale brown and finally dark to blackish brown at maturity, smooth, have a straight germ slit across the entire spore length present on one side (only in L. turgidum) or circumferential (visible as full-length slit on two opposite sides), also when immature; they have usually 2 large guttules, at least when immature; lack a sheath, but a narrow hyaline epispore c. 0.5 μm wide is sometimes visible in asci. Aberrant ascospores that are very variable in shape are a consequence of aberrant development depending on climatic factors.

Cultures

Ascospores of most Lopadostoma species germinate slowly on MEA (after few days to several weeks). Growth rates are slow, the colony radius is in the range of 15–20 mm after 1 mo at room temperature, only L. americanum, L. fagi and L. insulare grow slightly faster, while L. lechatii reaches less than 10 mm after 1 mo. Colonies of Lopadostoma cultures (Fig. 3) start off as flat and white, may develop scant or abundant aerial hyphae and turn yellow, rosy or brown, more pronounced on the reverse. Sometimes brown pigment diffuses through the agar. Most species, albeit not L. gastrinum and L. turgidum, produce a volatile substance, which becomes noticeable as a strong, unpleasant, varnish-like odour.

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Fig. 3

Lopadostoma cultures at room temperature. a, b. L. americanum (b. reverse); c. L. dryophilum (LG21); d, e. L. fagi (LF 1); f. L. gastrinum (LG2); g. L. insulare (LQM); h. L. lechatii (LG22, 61 d); i. L. linospermum (LPL); j–l. L. meridionale (j. LG; k, l. LG, PDA); m. L. quercicola (LG12); n–p. L. turgidum (LT2; p. 134 d). All on MEA except k, l. All after 35 d except h and p.

Asexual morphs

Libertella-like, only found in the following five species: L. americanum, L. fagi, L. linospermum, L. meridionale and L. turgidum. Conidia accumulate in yellow, orange, olivaceous or brown to black mucous drops or pycnidia (drops encased by a membrane), they are falcate, unicellular, hyaline, with uniform size among species, but their curvature varies somewhat, in its extreme they are nearly circular (in L. meridionale).

Ecology

Species of Lopadostoma occur exclusively in the bark of trees and shrubs, never immersed in decorticated wood.

Characters useful for distinction and identification of species, in combination: germ slit (on one ascospore side in L. turgidum, on both sides in all other species), ascospore size (several species), colour of the entostroma between the ostiolar necks (yellow-brown to olivaceous in L. dryophilum and L. linospermum, dark brown to black, e.g. in L. insulare and L. meridionale) and hosts. Strongly and irregularly projecting discs, stromata and ostioles are often a consequence of rapidly changing climatic conditions. As an example, a specimen of L. dryophilum (LG21) was collected on Q. petraea with smooth ectostromatic discs; re-collection from the same branches after heavy rain revealed many irregularly projecting pustules, ejected black spore pustules and variable, aberrant ascospores. Because of considerable overlap of ascospore sizes, the ranges given in the key are mean ± standard deviation of at least 30 measurements, excluding minima and maxima. The detailed description of the phenotype above should be consulted before using the key and the individual species descriptions.

TAXONOMY

SPECIES DESCRIPTIONS

Descriptions of accepted species are given in alphabetical order.

Lopadostoma ailanthi (G.H. Otth) Jaklitsch, J. Fourn. & Voglmayr, comb. nov. — MycoBank MB803802; Fig. 4a–e

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Fig. 4

a–e: Lopadostoma ailanthi (holotype). a. Ectostromatic disc; b. vertical stroma section; c, d. apical ascus rings in Lugol; e. ascospores showing germ slit (both sides visible in one spore). — f–s: Lopadostoma juglandinum. f–i. Ectostromatic discs (f. showing discoid ostioles; g. var. caryae; h. distinct ostioles in pale brown disc); j, k. vertical stroma sections; l–o. asci (o. in Lugol); p. ascospores showing germ slit; q, r. apical ascus rings in Lugol; s. ascospores (f, h–l, n–p, r. holotype F1318238; g. var. caryae K(M) 177255; m. var. caryae from NY; q, s. K(M) 177254). — Scale bars: a = 0.5 mm; b, f, j, k = 0.8 mm; c, d = 7 μm; e, p, q, s = 5 μm; g = 2.2 mm; h, i = 0.3 mm; l–o, r = 10 μm.

Basionym. Phaeosperma ailanthi G.H. Otth (as P. ailanthi (Otth) Nke.), Mitth. Naturf. Ges. Bern 1870: 101. 1870.

Holotype. SWITZERLAND, Bern, Thun, near Steffisburg, in a garden, on a dead twig of Ailanthus altissima (given as Ailanthus glandulosa), without date, G.H. Otth, Nr. 51 (B).

Stromata immersed in bark, subglobose, c. 3 mm diam and 2.5 mm high, appearing on the bark surface as a circular or elliptic black ectostromatic disc up to 2.8 × 1.4 mm, compact, surrounded by a black line. Tissue within the black line dark brown to black. Perithecia monostichous or distichous, c. 1 mm high, 0.5–0.8 mm diam; ostiolar necks long, convergent in the disc. Asci cylindrical, containing 8 uniseriate ascospores, apical ring flat, amyloid, (1.8–)2–2.3(–2.5) μm wide and (0.4–)0.6–0.9 μm high (n = 15). Ascospores oblong or narrowly ellipsoid, (10.5–)11.7–15.0(–16.5) × (4.0–)4.3–5.5(–6.0) μm, l/w (2.1–)2.4–3.2(–4.2) (n = 33), dark brown, smooth, not or only slightly compressed, germ slit circumferential, straight.

Distribution & Habitat — Switzerland, in corticated branch of Ailanthus altissima; only known from the type specimen.

Notes — Otth (1870) described this taxon as Phaeosperma ailanthi (Otth) Nke. after Nitschke had told him in a letter that it belongs to Phaeosperma. However, the correct citation is Phaeosperma ailanthi G.H. Otth. Nitschke′s impact could be honoured as Phaeosperma ailanthi Nitschke ex G.H. Otth, which is not necessary. On the label of the type specimen Otth also wrote the names Anthostoma ailanthi Otth and Diatrype ailanthi Otth. These names have never been published, but Saccardo (1895: 25) included the name Anthostoma ailanthi (Otth) Nke. in Otth, apparently as his own interpretation.

This fungus is clearly a species of Lopadostoma; however, in the absence of DNA data its status as a species distinct from L. dryophilum is preliminary, because the type material is scant, consisting only of two halves of mostly effete stromata, which are infested by Eurotium herbariorum. The wood is lightweight, pale-coloured and ring-pored, which confirms Ailanthus. Lopadostoma dryophilum, which has a similar ascospore size, occurs in the same area. Recent attempts to find L. ailanthi have been without success.

Lopadostoma americanum Jaklitsch, J. Fourn., J.D. Rogers & Voglmayr, sp. nov. — MycoBank MB803803; Fig. 5

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Fig. 5

Lopadostoma americanum (WU 32033, culture LG8). a–o. Sexual morph: a. surface view of stromata; b. ectostromatic disc; c, d. transverse sections of a stroma (c. ostiolar level; d. perithecial level); e, f. vertical sections of a stroma; g–i, l. ascospores (l. showing germ slit); j, k. apical ring in Lugol; m–o. asci (o. in Lugol). — p–u. Cultures and asexual morph: p. colony (64 d); q. conidial drops (68 d); r–u. conidia (68 d) (p–u: all on MEA at 25 °C). — Scale bars: a = 1 mm; b–e = 0.5 mm; f = 0.3 mm; g–l = 3 μm; m, n = 10 μm; o, s, t = 7 μm; q = 0.2 mm; r = 15 μm; u = 5 μm.

= Anthostoma dryophilum (Curr.) Sacc. sensu Ellis & Everhart (1892).

Holotype. USA, West Virginia, Upshur Co., Audra State Park, on corticated branch of Quercus sp. (white oak), 29 Aug. 2008, J.D. Rogers (WU 32033, ex-type culture CBS 133211 = LG8).

Etymology. Occurring in America.

Ectostromatic discs flat or convex, often ill-defined, circular or ellipsoid in outline, 0.7–1 mm in their greatest dimension, projecting to 0.3 mm above the host surface, roughened, carbonaceous, shiny in places; ostioles opening separately in the disc, inconspicuous, umbilicate. Stromata for the most part immersed in bark, pustulate-erumpent, separate, scattered, rarely in contact, subglobose, 2–3 mm diam, delimited from surrounding bark by a black carbonized line; the latter 80–120 μm thick, irregular in outline, reaching the wood surface and spreading over it between adjacent stromata. Tissue between ostiolar necks dark yellow-brown, grey to black, woody; tissue around and beneath the perithecia composed of brownish, scarcely altered bark tissue, in places mixed with whitish mycelium. Perithecia 6–15 per stroma, arranged in valsoid configuration, monostichous in smaller stromata, polystichous in larger ones, subglobose to ovoid, often laterally compressed, 0.4–0.9 mm diam, with long ostiolar necks converging toward the ectostromatic disc. Asci cylindrical, with 8 uniseriate ascospores, spore part (50–)55–70(–81) × (5.0–)6.0–7.5(–8.3) μm (n = 34), sometimes fusiform due to partly overlapping biseriate or oblique ascospores, flat amyloid apical ring (1.3–)1.5–1.8(–2.0) μm diam, 0.5–0.7(–0.8) μm high (n = 35); stipe up to nearly as long as the spore part. Ascospores oblong to narrowly ellipsoid, (8.2–)9.2–11.5(–13.7) × (3.3–)3.5–4.2(–4.7) μm, l/w (1.9–)2.3–3.0(–3.6) (n = 62), dark to blackish brown, smooth, with 2 guttules when young, with commonly visible, straight, circumferential germ slit.

Cultures and asexual morph — On MEA after 35 d at room temperature colony radius 19–29 mm (to 36 mm after 4.5 mo). Colony typically with angular or irregular outline; margin colourless, diffuse; colony surface thick, white, covered by highly variable tufts or pustules of aerial hyphae; colony reverse rosy with yellow tone; odour none to unpleasant. Conidia forming after c. 55 d at room temperature in mucous, initially hyaline drops c. 0.7–1 mm diam that turn yellowish, after 2 mo olivaceous and eventually black. Asexual morph (on MEA after 68 d at 25 °C) libertella-like. Conidia falcate, (17–)18.5–22.5(–24.5) × (1.1–)1.2–1.5 μm, l/w (13–)14–17(–19) (n = 30), hyaline, 1-celled, smooth, upper end subacute, base truncate, curved to nearly semicircular. Growth on PDA slightly faster than on MEA; colony nearly circular, with uneven white mat, colourless, white to yellowish margin, and yellowish reverse; after > 1 mo forming large thick yellowish pustules but no conidial drops.

Distribution & Habitat — North America, on Quercus spp. (white oaks).

Other specimen examined. USA, New Jersey, Gloucester County, Newfield, on dead limbs of Quercus alba, 11 Oct. 1891, R.A. Harper, N.A.F. (without number; NY).

Notes — The only available material that yielded a culture (WU 32033) contains mostly cut or depauperate stromata. The dimensions do probably not reflect the entire variation range that can be expected. Morphologically, L. americanum is similar to other species on Quercus with dark stroma tissues between the ostioles. It is one of the few species on Quercus that produces an asexual morph on MEA. Unlike other species of Lopadostoma, the conidial drops turn olivaceous and eventually black.

We establish here the new name L. americanum for material that J.B. Ellis (see Ellis & Everhart 1892: 581) erroneously called Anthostoma dryophilum (Curr.) Sacc. The latter name was based on Sphaeria dryophila Curr., which was established on a British specimen collected by Hooker in Weybridge, Surrey and has distinctly larger ascospores than L. americanum. Anthostoma dryophilum (Curr.) Sacc. var. minor Cke. (1876; Grevillea V, p. 32, pl. 75/13 as Diatrype dryophila var. minor), may however be a different species of Lopadostoma, particularly due to the different hosts of the red oak group (Quercus coccinea, Q. nigra). Morphologically, it is similar to L. americanum, but differs in more effused, widely erumpent but less prominent compound stromata, which are covered by blackened epidermis. Several or many minute, ill-defined, tubercular discs 0.2–0.7 mm diam per compound stroma split the bark irregularly; individual stromata contain 6–15 perithecia and the internal tissues are dark brown. The spore part of asci measure (61–)66–82(–84) × (5.3–)5.7–7.6(–8.3) μm (n = 10), and the ascospores (8.3–)9.5–12.2(–14.0) × (3.5–)3.8–4.5(–5.2) μm, l/w (2.0–)2.3–2.9(–3.3) (n = 30), slightly lighter and more reddish brown than in L. americanum and partly nearly rhomboid. Asci are only slightly longer than in L. americanum and stroma features vary considerably among specimens, therefore only DNA data of freshly collected specimens would provide certainty whether or not these forms represent different species. Several specimens of Anthostoma dryophilum var. minor of the Ellis Collection are housed in NY, all from New Jersey, Gloucester County, Newfield, on bark of Quercus coccinea, no date given; type of A. dryophilum var. minor (N.A.F. 87; no other information); same locality, from 22 May 1893.

Lopadostoma dryophilum (G.H. Otth) Jaklitsch, J. Fourn. & Voglmayr, comb. nov. — MycoBank MB 803804; Fig. 6

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Fig. 6

Lopadostoma dryophilum. a–d. Ectostromatic discs; e, f. transverse stroma section (e. ostiolar level; f. perithecial level); g–i. vertical stroma sections; j–m. asci (j. fresh, in water; m. in Lugol); n–q. apical ascus rings (o–q. in Lugol); r. ascospores; s–u. ascospores showing germ slit (s, t. germ slit on both sides of the same ascospore) (a, c, d, e, i, j, l, n–p, s, t: LG21; b, k, m: holotype of Sphaeria dryophila K(M) 177257; f–h: JF08196; q, u: lectotype of L. morthieri G 00111563; r. holotype of P. dryophilum). — Scale bars: a, c, f = 1 mm; b, d, e, i = 0.5 mm; g, h = 0.8 mm; j, l = 15 μm; k, m, r = 10 μm; n, p, s, t = 5 μm; o, q, u = 7 μm.

Basionym. Phaeosperma dryophilum G.H. Otth, Mitt. Naturf. Ges. Bern Nr. 654–683: 42. 1868.

= Sphaeria (Diatrype) dryophila Curr., Trans. Linn. Soc. London 22: 269. 1859 [non Sphaeria dryophila Schwein., Trans. Amer. Philos. Soc., Ser. 2, 4, 2: 226. 1832.

= Anthostoma dryophilum (Curr.) Sacc., Syll. Fung. 1: 308. 1882.

= Lopadostoma morthieri (Fuckel) Schrantz, Bull. Trimestriel Soc. Mycol. France 76: 370. 1960 (publ. 1961).

= Quaternaria morthieri Fuckel, Jahrb. Nassauischen Vereins Naturk. 23–24: 229. 1870 (1869–1870).

Holotype of the basionym Phaeosperma dryophilum. SWITZERLAND, Bern, Bremgartenwald, on Quercus sp. (Q. petraea or Q. robur), no date given, (B 70 0014745; as Valsa tumida). Epitype here designated: AUSTRIA, Niederösterreich, Gießhübl-Perchtoldsdorf, on branches of Quercus petraea, soc. old Diatrypella quercina and Enchnoa infernalis, 25 Mar. 2012, H. Voglmayr (WU 32035; ex-epitype culture CBS 133213 = LG21; MBT175915).

Ectostromatic discs dark brown, grey to black, flat, slightly convex or concave, often surrounded by typically darkened, ruptured, grey periderm, sometimes in stellate manner, 0.4–3 mm in their greatest dimension, often coalescent in small groups or several scattered on a common, slightly convex, pulvinate stroma, projecting 0.3–1.6 mm above the host surface, circular or elliptic in outline, smooth to roughened, often with slightly projecting black ostioles. Ostioles opening separately in the disc, inconspicuous or raised and bluntly rounded 80–120 μm high, 50–220 μm diam. Stromata (part stromata in case of widely effused entire stromata) pustulate, erumpent through the bark, subglobose, 2–6 mm wide, 1–2.6 mm high, surrounded by a black stromatic line, the latter 100–200 μm thick, irregular in outline, reaching the wood surface and spreading over it between adjacent stromata or more commonly spreading widely and encompassing several coalescent stromata. Tissue between ostiolar necks typically distinctly yellow-brown to olivaceous, at times weakly developed, woody, not releasing pigment in 10 % KOH; tissue around and beneath perithecia brownish, composed of bark tissue mixed with white fungal tissue in variable proportions, at times of hardly altered bark and compact, rarely blackish brown. Perithecia 2–25 per stroma, arranged in valsoid configuration, monostichous in smaller stromata, polystichous in larger ones, subglobose or flask-shaped, 0.3–1 mm diam, somewhat laterally compressed when crowded, with short to long ostiolar necks converging toward the disc. Asci long cylindrical, variably stipitate, containing (6–)8 uniseriate, sometimes partly biseriate or obliquely overlapping ascospores, spore part (90–)98–120(–126) × (6–)7–10(–13) μm (n = 47); apical ring flat, amyloid, refractive in 3 % KOH, (2.0–)2.2–2.5(–3.0) μm wide and (0.5–)0.6–0.9(–1.2) μm high (n = 54); asci longer and broader in water than in 3 % KOH. Ascospores (10–)13–17.5(–20) × (3.3–)4.5–5.5(–6.3) μm, l/w = (1.9–)2.6–3.6(–5.3) (n = 210), oblong, narrowly ellipsoid or narrowly fusiform, unicellular, dark brown to nearly black, equi- to slightly inequilateral or slightly curved (nearly banana-shaped), not compressed, with straight, circumferential germ slit and 2 large and sometimes several small guttules (in water and KOH).

Cultures and asexual morph — On MEA after 35 d at room temperature colony radius 18–20 mm (after 4.5 mo centrally inoculated plate nearly entirely covered). Colony typically circular, thin, first with cottony aerial hyphae, soon flattening and inconspicuous; surface and reverse distinctly yellow to pale orange, often with a rosy tone, reverse more intensely coloured; sometimes turning dull olive-brown from the centre; margin often lighter or white, well-defined, sometimes slightly lobed; odour fruity or unpleasant, ‘chemical’, varnish-like; in the latter case growth often stopping soon. No conidia detected within 4.5 mo. Growth on PDA slightly faster than on MEA; colony surface white by aerial hyphae, turning pale brown from the centre; reverse dull yellow, hard brownish pustules but no conidia formed.

Distribution & Habitat — Europe, in corticated branches of Quercus petraea and probably Q. robur; apparently more common in Western Europe.

Other specimens examined. FRANCE, Ariege, Rimont, Las Muros, on branch of Quercus petraea, 30 Aug. 2009, J. Fournier JF 09233 (WU 32034; culture LG11); ibid., same host, 25 Mar. 2012, J. Fournier JF 12038 (WU 32037; culture LG24); Rimont, trail from Grillou to Sourroque, on branch of Quercus petraea, 13 Mar. 2012, J. Fournier JF 12029 (WU 32036; culture LG23); Rimont, Saurine, elev. c. 450 m, on bark of Quercus petraea, 21 Nov. 2008, J. Fournier JF 08196; Pyrénées-Atlantiques, Oloron, Préchacq-Josbaig, Bois de Josbaig, Quercus cf. petraea. – GERMANY, Hessen, Oestrich, Vorderwald, no date given, Fuckel, on branch of Quercus petraea (G 00111565, as Quaternaria morthieri). – SPAIN, Asturias, Soto de Los Infantes, near Viescas, on branches of Quercus petraea, W. Jaklitsch & H. Voglmayr (WU 32097). – SWITZERLAND, Jura mountains, near Neuchatel, on branch of Quercus cf. petraea, 28 Apr. 1867, P. Morthier, teste G. Colomb-Duplan (G 00111566, as Quaternaria morthieri, lectotype of Q. morthieri here selected; MBT175914); ibid., 15 Nov. 1867, P. Morthier (G 00111563, as Quaternaria morthieri); ibid., Mar. 1871 (G 00111564, as Quaternaria morthieri). – UNITED KINGDOM, Surrey, Weybridge, on decaying branches of Quercus sp. (probably Q. robur, Sept. 1856, ex herb. F. Currey (K(M) 177257, holotype of Sphaeria dryophila, given as the unpublished name Valsa dryophila Curr. on the label); no locality given, Feb. 1939, C.G.C. Chesters (only culture CBS 107.39 = LG41 sequenced).

Notes — Diagnostic of L. dryophilum are the large asci and ascospores as well as the distinctly yellow-brown to olivaceous entostroma between ostiolar necks, which is similar to L. linospermum on Pistacia lentiscus. In overmature material this tissue may be dark brown. The black stromatic line is usually conspicuous around individual stromata but may sometimes be overlooked when only present around widely effused stromata that contain several perithecial groups.

Comments to the selection of the basionym: Phaeosperma dryophilum G.H. Otth is the basionym of L. dryophilum. Otth (1868) attributed the taxon to Nitschke, because the latter had told him about the possible generic affiliation of the fungus. However, there is no indication that Nitschke provided a diagnosis, therefore a more complete but long and unnecessary citation would be Phaeosperma dryophilum Nitschke ex G.H. Otth. As addressed by Otth (1868: 42) he had misidentified the fungus in 1863 (Otth 1863: 79) as Valsa tumida and deposited the type material under this name. Sphaeria (Diatrype) dryophila Curr. (1859) is older than P. dryophilum, but a later homonym of Sphaeria dryophila Schwein. (1832), a fungus described from leaves, i.e. not representing a Lopadostoma. Currey (1859) described the fungus as a Sphaeria and put the name Diatrype in parentheses to relate it to the system of Fries’ Summa Vegetabilium Scandinaviae, while he obviously did not accept at that time of splitting Sphaeria into separate genera by Fries and other authors, explicitly writing on page 261: “In the Summa Vegetabilium Scandinaviae the Sphaeriae included in the above divisions are thrown into distinct genera...”. He preferred to maintain the large genus Sphaeria with several sections and divisions. Saccardo (1882: 308) ignored Currey’s intentions and the generic name Sphaeria, but simply cited the name as Diatrype dryophila Curr. and combined it as Anthostoma dryophilum (Curr.) Sacc. Index Fungorum took up this name as Anthostoma dryophilum Sacc. (1882), defining Sphaeria dryophila Curr. 1859 as a replaced synonym. However, Phaeosperma dryophilum G.H. Otth (1868) is older than Anthostoma dryophilum Sacc. (1882) and therefore the valid basionym of L. dryophilum. The name Anthostoma dryophilum (Curr.) Sacc. was only rarely used in Europe, but erroneously by J.B. Ellis for a different fungus in North America (see above under L. americanum).

Lopadostoma fagi Jaklitsch, J. Fourn. & Voglmayr, sp. nov. — MycoBank MB803805; Fig. 7

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Fig. 7

Lopadostoma fagi. a–n. Sexual morph: a. panoramic view of stromata; b. two stromata in face view; c. ectostromatic disc; d. transverse stroma section; e, f. vertical stroma sections; g–i. asci (g. in Lugol); j–l. apical ring (k, l. in Lugol); m, n. ascospores showing germ slit (n. compressed, showing circumferential germ slit). — o–r. Cultures and asexual morph: o. colony on PDA (RT, 55 d); p. conidial drop; q, r. conidia (p–r: all on MEA at 25 °C after 48 d. a–f, i, l, m, p–r: LF; g, h, j, k, n, o: LF2). — Scale bars: a = 1.5 mm; b, p = 1 mm; c, e, f = 0.2 mm; d = 0.3 mm; g–i, q, r = 10 μm; j, k = 5 μm; l = 7 μm; m, n = 3 μm.

Holotype. AUSTRIA, Niederösterreich, Mauerbach, on a corticated branch of Fagus sylvatica, 13 June 2011, W. Jaklitsch (WU 32039; ex-type culture CBS 133206 = LF1).

Etymology. For its occurrence on Fagus.

Stromata widely effused on recently dead branches, up to 30–40 cm long, uniting numerous small, typically densely gregarious, separate or coalescent, flattened pustules 1–2 mm diam, slightly raising the periderm, discolouring it dark silvery grey above the pustules, contrasting with the surrounding reddish brown colour. Pustules pierced at their centre by a dull black ectostromatic disc 0.37–0.84 mm in its greatest dimension (av. = 0.53 mm, n = 90), circular or elliptic, flat, slightly convex or concave, projecting 120–250 μm above the periderm, surrounded by teeth-like remnants of the ruptured periderm, sometimes containing distinctly papillate ostioles. Tissue between the ostioles blackish, soft-textured, tissue surrounding perithecia somewhat powdery, composed of white fungal tissue mixed with yellowish brown bark cells; tissue beneath the perithecia compact, composed of nearly unaltered bark, delimited in the lower part by a thin, often inconspicuous, dark brown to black stromatic line; loosening bark below stromata seated on a thick dark brown felty layer spreading over the wood surface. Perithecia (3–)6–8 in a cluster, monostichous, circinate, flask-shaped or depressed-globose, at the periphery inclined toward the centre, 250–750 μm high, 330–620 μm wide, with long ostiolar necks converging toward the disc, opening separately in the disc. Ostiolar openings umbilicate, inconspicuous. Asci cylindrical, spore-bearing part (53–)64–79(–83) × (5.0–)5.3–6.0(–7.0) μm (n = 31), with 8 uniseriate ascospores; apical ring (1.6–)1.9–2.2(–2.5) μm wide, (0.6–)0.7–1.1(–1.3) μm high (n = 35). Ascospores oblong or narrowly ellipsoid, (6.5–)7.7–9.8(–11.8) × (3.2–)3.7–4.2(–4.8) μm, l/w (1.4–)1.9–2.5(–2.9) (n = 121), unicellular, blackish brown, smooth, with a circumferential, straight germ slit, with 2 large guttules, at least when immature.

Cultures and asexual morph — Ascospores germinating slowly (after 1–4 wk on 2 % MEA). On MEA after 35 d at room temperature colony radius c. 25 mm (c. 40 mm after 2 mo; colony entirely covering a centrally inoculated plate after c. 4 mo); colony circular with well-defined margin, first white, covered by a variable white mat or tufts of aerial hyphae, turning rosy, particularly at the margin and on the reverse, sometimes mixed with yellow; odour indistinct to slightly strongly ‘chemical’, varnish-like (isolate LGC). Conidia forming after 1–2 mo in yellow to orange mucous drops to c. 3 mm diam, falcate, (18–)19–23(–27) × 1.4–1.7 μm, l/w (11.5–)13–15.7(–17.6) (n = 30), unicellular, hyaline, with acute upper end and narrowly truncate lower end. On PDA colony similar, less rosy, more yellow, sometimes aerial hyphae forming white tufts or pustules around the plug or grey or brown spots appearing in the centre. Conidia formed after 48 d at room temperature in orange conidial drops (0.3–)0.8–2 mm diam in the colony centre, eventually (after 4–5 mo) turning to large mucous brown pustules.

Distribution & Habitat — Europe, in corticated branches of Fagus sylvatica; common on this host; found once on Corylus avellana.

Other specimens examined (all on corticated branches of Fagus sylvatica except where noted). AUSTRIA, Kärnten, St. Margareten im Rosental, grid square 9452/4, Stariwald, 8 June 1992, W. Jaklitsch W.J. 30 (WU 32099); Zabrde, 16 Aug. 1996, W. Jaklitsch W.J. 923 (WU 32100); Niederösterreich, Hainbuch, grid square 7763/1, 28 Sept. 1996, W. Jaklitsch; Mauerbach, grid square 7762/4, 16 May 1992, W. Jaklitsch W.J. 25 (WU 32098); Weidlingbach, 3 Mar. 2012, W. Jaklitsch & H. Voglmayr (WU 32041; culture LF3); Steiermark, Berghausen, Graßnitzberg, grid square 9259/4, 20 Sept. 1996; Klöch, Koglwald, grid square 9261/2, 17 Sept. 1996 (GZU), W. Jaklitsch; Mönichkirchen, Tränktörl-Glashütte, 1 Aug. 2010, W. Jaklitsch (WU 32038; culture LF); Pöllau, Schönauklamm, grid square 8760/2, 12 Sept. 2002, W. Jaklitsch. – FRANCE, Ariege, Rimont, 1.5 km from the village on the road D18, 14 Nov. 2011, J. Fournier JF 11169 (WU 32040; culture LF2). – GERMANY, Hessen, NW Schifferberg, grid square 5418/1, elev. 210 m, soc. Biscogniauxia marginata, 31 Mar. 2007, W. Schößler, comm. K. Siepe SI 10/2007 (WU 32042). – UNITED KINGDOM, England, Yorkshire, Worksop, Rotherham, Anston, Anstonstones Wood, on a corticated branch of Corylus avellana, 16 May 2011, W. Jaklitsch (WU 32043; culture LGC).

Notes — Stromata of L. fagi are similar to those of L. turgidum, but differ in slightly larger ectostromatic discs that may contain distinctly papillate ostioles, smaller, particularly narrower ascospores, a circumferential germ slit, slow germination and rosy colour of colonies on MEA. Both species often occur in the same beech forest and are indistinguishable in the field. The only specimen found on Corylus yielded slightly deviant sequences and a stronger odour in MEA cultures. Vasilyeva & Scheuer (1996), who already noticed the circumferential germ slit, reported this species as Lopadostoma sp. from six localities in Austria.

Lopadostoma gastrinum (Fr.) Traverso, Fl. Ital. Crypt. 2, 1: 169. 1906. — Fig. 8

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Fig. 8

Lopadostoma gastrinum. a–d. Ectostromatic discs; e. superficial stroma with projecting ostioles; f, g. transverse stroma sections (f. ostiolar level); h–j. vertical stroma sections; k–m. asci; n. ascospores laterally collapsing in lactic acid; o, p. ascospores showing germ slit; q, r. apical ascus ring in Lugol; s. colony on MEA at 25 °C after 63 d (a: LG7; b, f, g, i: LG5; c, j: LG20; d, s: LG26; e, l, m: LG6; h: JF12024; k, o, p: LG2; n, q, r: LG4). — Scale bars: a = 1.5 mm; b, c, f, g, j = 0.5 mm; d = 0.2 mm; e, i = 1 mm; h = 2 mm; k–n = 10 μm; o–r = 5 μm.

Basionym. Sphaeria gastrina Fr., Syst. Mycol. (Lundae) 2, 2: 379. 1823.

= Anthostoma gastrinum (Fr.) Sacc., Atti Soc. Veneto-Trentino Sci. Nat. Padova 2: 143. 1873.

? = Lopadostoma formosum (Ellis & Everh.) P.M.D. Martin, J. S. African Bot. 42, 1: 75. 1976.

Neotype proposed here. ITALY, Lombardia, Brescia, Sopraponte, on branch of Ulmus minor, 21 Oct. 2011, W. Jaklitsch (WU 32046; ex-neotype culture CBS 134632 = LG4; MBT175922).

Ectostromatic discs circular, oblong or elliptic, 1–5.2 mm long, at times coalescent in small groups, typically surrounded by ruptured periderm, projecting up to 1 mm above the host surface, flat or convex, black, smooth or roughened. Ostioles opening separately in the disc, mostly umbilicate and inconspicuous, or papillate, sometimes strongly projecting above the disc surface, bluntly rounded to narrowly conical 0.2–0.9 mm high, 0.3–0.5 mm diam at the base, fragile. Stromata immersed in bark or erumpent, rarely superficial, particularly after the bark has split off, scattered or crowded; pustulate, bluntly conical or subglobose, 1.7–3.3(–12) mm diam, surrounded by a black stromatic line, the latter 40–250 μm thick, irregular in outline, reaching down to the wood surface and spreading over it between adjacent stromata or surrounding several coalescent stromata. Tissue between ostiolar necks white or pale brown, tissue around and beneath perithecia typically light coloured, whitish to pale brown, composed of bark tissue mixed with white fungal tissue in variable proportions, at times bark hardly altered. Perithecia arranged in valsoid configuration, mostly 2–25, rarely to c. 100 per stroma, monostichous in smaller stromata, polystichous in larger ones, subglobose or flask-shaped, 0.4–1 mm diam, somewhat laterally compressed when crowded, with short to long ostiolar necks converging toward the disc. Asci cylindrical, spore part (78–)88–110(–119) × (6.0–)6.5–8.0(–8.7) μm (n = 25), containing 8 uniseriate ascospores; apical ring thin, amyloid, (1.5–)1.8–2.2(–2.3) μm wide, (0.5–)0.7–1.1(–1.3) μm high (n = 26). Ascospores (8.8–)10.5–12.8(–14.5) × (3.7–)4.5–5.5(–6.0) μm, l/w = (1.6–)2.0–2.7(–3.3) (n = 106), oblong or narrowly ellipsoid, laterally compressed, becoming distorted and collapsing on the narrow side in lactic acid and broad side unchanged or broader than in KOH, smooth, with two guttules particularly when young; germ slit in 3 % KOH distinct but thin, mostly on the narrow side, circumferential.

Cultures — Colony radius at room temperature on MEA 15–17 mm after 35 d (22–26 mm after 2 mo, centrally inoculated plate not entirely covered after 4.5 mo); colony circular to slightly irregular, surface becoming covered by a thick and dense white mat of aerial hyphae, at times developing (greyish) brown spots or pustules, particularly in the colony centre, reverse whitish to yellowish, becoming greyish brown to black from the centre, odour indistinct; no asexual morph formed within 6 mo. Growth on PDA similar, colony dull whitish to light brownish, becoming zonate; no asexual morph detected.

Distribution & Habitat — Europe, in corticated, rarely decorticated branches of Ulmus spp., common; frequently found also on other hosts such as Acer, Carpinus or Prunus.

Other specimens examined. AUSTRIA, Burgenland, Bad Sauerbrunn, Hirmer Wald, grid square 8264/1, on branch of Carpinus betulus, 13 July 2004, W. Jaklitsch; Niederösterreich, Gießhübl, on branch of Carpinus betulus, 18 Mar. 2012, H. Voglmayr (WU 32051; culture LG20); Großenzersdorf, Lobau, grid square 7865/1, on branch of Ulmus minor, 27 Feb. 2000, W. Jaklitsch; Hagenbrunn, Bisamberg-east side, grid square 7664/3, on branch of Carpinus betulus, 30 Oct. 1999, W. Jaklitsch; Vienna, 13th district, Schönbrunn-Gloriette, grid square 7863/2, on branch of Acer campestre, 26 Feb. 2003, W. Jaklitsch W.J. 2063 (WU 32102); 19th district, Himmelstraße, on branch of Carpinus betulus, 4 Apr. 2010, W. Jaklitsch (WU 32044; culture LG1); ibid., on branch of Ulmus glabra, 24 Apr. 2010, W. Jaklitsch (WU 32045; culture CBS 133210 = LG2); 22nd district, Lobau, near Panozzalacke, grid square 7865/1, on branch of Ulmus minor, 4 May 1996, W. Jaklitsch W.J. 852 (WU 32101); ibid., on Ulmus minor, 9 Mar. 2002, W. Jaklitsch W.J. 1858 (W); ibid., on Ulmus minor, 30 Apr. 2003, W. Jaklitsch W.J. 2108 (W); ibid., on branch of Prunus padus, 18 Mar. 2012, W. Jaklitsch (WU 32050; culture LG18); ibid., on Ulmus minor, 7 Apr. 2012, W. Jaklitsch (WU 32052; culture LG26); 23rd district, Maurer Wald, grid square 7863/1, on Ulmus minor, 7 Oct. 2000, W. Jaklitsch. – FRANCE, Ariege, Rimont, Las Muros, on branch of Acer campestre, 14 Mar. 2011, J. Fournier JF 11016 (WU 32048; culture LG6); ibid., on branch of Ulmus minor, 9 Nov. 2011, J. Fournier JF 11166 (WU 32047; culture LG5); ibid., on branch of Acer campestre, 12 Nov. 2011, J. Fournier JF 11170 (WU 32049; culture LG7). – GREECE, Corfu, Liapades, on branch of Ulmus minor, 20 Apr. 2012, W. Jaklitsch (WU 32053); Skripero, shortly before the village heading north, on branch of Ulmus minor, 23 Apr. 2012, W. Jaklitsch & H. Voglmayr (WU 32054); Agia Anna, on branches of Ulmus minor, 23 Apr. 2012, W. Jaklitsch (WU 32055). – POLAND, Pulawy-Kepa, on Ulmus sp., 17 Nov. 1963, J. Kochman (NY; Mycotheca Polonica, fasc. XIV, no. 343). – SPAIN, Cataluña, Val d’Aran, Puerto de Bonaigua, elev. c. 2 000 m, on branch of Sorbus chamaemespilus, 16 May 1986, F. Candoussau (WU 32092).

Notes — The main arguments for how to define and circumscribe L. gastrinum are the plurivorous character and its primary occurrence on Ulmus, as already noted by Fries (1823), who mentioned Ulmus as the first host. No type material has been found at C, S and UPS. According to S. Ryman (pers. comm.), there is a specimen in UPS, which bears the text ‘Sphaeria gastrina, junior? Lund’ on the label, written by Elias Fries, i.e. Fries was apparently not sure of the determination of this specimen. The material is not sent out.

Lopadostoma gastrinum is common on Ulmus spp., occurs also on various other hardwood trees, but has not been detected on species of Fagus and Quercus. Stromata of this species are very variable, sometimes distinctly projecting or even superficial, which made a morphological delimitation of other species difficult in the pre-molecular era. Stroma development and ostioles are much dependent on climate conditions, particularly repeated drying and wetting in nature. Typical of L. gastrinum is its light, often nearly white entostroma in all parts, which is similar to that of L. lechatii. However, the latter species seems to be confined to Carpinus and has distinctly smaller ascospores. Ascospores of L. gastrinum are distinctly laterally compressed unlike those of other species of the genus. However, it is difficult to separate measurements of wide and narrow sides, therefore the whole range of ascospore widths is given above. No asexual morph has been detected in L. gastrinum on MEA and PDA.

The combination Phaeosperma gastrinum (Fr.) Nitschke ex G.H. Otth, Mitth. Naturf. Ges. Bern: 42 (1869) [1868] was not published by Otth, but is based on an error made by Saccardo. Only P. dryophilum was published by Otth in the cited paper.

Lopadostoma insulare Jaklitsch, J. Fourn. & Voglmayr, sp. nov. — MycoBank MB803806; Fig. 9

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Fig. 9

Lopadostoma insulare. a–c. Ectostromatic discs (b. showing projecting ostioles); d. transverse stroma section; e, f. vertical stroma sections; g–i. asci (i. in Lugol); j, k. ascospores showing germ slit (j. compressed, showing slit on both sides); l–n. apical ascus rings in Lugol (a, e, g, h, j, n: LG32; b–d, f, i, k–m: LQM). — Scale bars: a, d, e = 0.7 mm; b = 0.5 mm; c, f = 1 mm; g–i = 10 μm; j–n = 3 μm.

Holotype. SPAIN, Islas Baleares, Mallorca, Es Capdella, between Camí del Graner del Delme and Torrent de Galatzó, on a branch of Quercus ilex lying in wet grass, 16 Nov. 2010, W. Jaklitsch (WU 32056; ex-type culture CBS 133214 = LQM).

Etymology. Occurring on islands.

Ectostromatic discs usually ill-defined, massive, rounded or more or less ellipsoid, 0.7–4.8 mm diam, often coalescent into linear rows or irregular aggregates 9–16 mm long, projecting 0.4–2 mm above the host surface, flat or convex, tubercular or verrucose, black. Ostioles opening separately in disc, variable, umbilicate in the disc or papillate and bluntly rounded, or conical and projecting to 0.8 mm above the disc surface, 0.3–0.5 mm diam at the base, 0.1–0.3 mm diam at the apex, fragile. Stromata subglobose pulvinate or more or less effused, 2.3–10 mm diam, immersed in bark tissue, widely and irregularly erumpent; superficial on wood upon bark disintegration, laterally delimited by a thin, often inconspicuous black carbonized stromatic line, the latter irregular in outline, extending down to the wood surface and spreading over it between adjacent stromata. Tissue between ostiolar necks conspicuously dark greyish brown to blackish, woody, turning lighter to pale brown around and beneath the perithecia, composed of bark tissue mixed with white fungal tissue. Perithecia 3–80 per stroma, arranged in valsoid configuration, often densely crowded, monostichous in smaller stromata, polystichous in larger ones, subglobose or flask-shaped, 0.4–1.2 mm diam, often laterally compressed, with short to long ostiolar necks converging toward disc. Asci cylindrical, long-stipitate, spore part (53–)60–72(–79) × (4.5–)5.5–7.0(–7.5) μm (n = 36), with 8 uniseriate ascospores, sometimes oblique or biseriate in the middle; apical apparatus c. 4.5 μm high and wide, containing a flat ring, refractive in KOH, dark blue in Lugol, (1.5–)1.6–1.8(–2.0) μm wide, (0.4–)0.5–0.7(–0.8) μm high (n = 30). Ascospores narrowly ellipsoid or oblong, not or indistinctly compressed, (6.2–)7.2–9.2(–11.0) × (3.0–)3.5–4.0(–4.7) μm, l/w = (1.7–)1.9–2.5(–3.1) (n = 85), chocolate to blackish brown, smooth, with circumferential, straight, germ slit, with 2 guttules when young, without dwarf cell, sometimes a narrow sheath on 1 side visible in asci.

Cultures — Colony radius at room temperature on MEA 27–30 mm after 35 d, centrally inoculated plate nearly entirely covered after 4.5 mo; colony circular, flat, surface covered by a thin mat of aerial hyphae, radial at the margin, white, slowly turning pale rosy, indistinctly zonate, slightly farinose; reverse yellowish to rosy, odour unpleasant; no asexual morph formed within 5 mo. On PDA colony similar to MEA, but more zonate, growth slightly more slowly.

Distribution & Habitat — Southern Europe, only known from two specimens collected in the islands Corfu and Mallorca on Quercus coccifera and Q. ilex.

Other specimen examined. GREECE, Corfu, Agia Anna, on corticated branch of Quercus coccifera, 23 Apr. 2012, H. Voglmayr & W. Jaklitsch (WU 32057; culture LG32).

Notes — The two known specimens of L. insulare differ considerably from each other. The distinctly projecting ostioles of the holotype specimen from Mallorca are apparently a consequence of the wet habitat on the ground, and its stromata may at first sight be identified as belonging to Camarops or Valsaria. The entostroma of this species is conspicuously dark. Ascospores of L. insulare are amongst the smallest in Lopadostoma and help to distinguish this species from L. meridionale, which occurs on the same hosts and forms an asexual morph unlike L. insulare.

Lopadostoma juglandinum (Rehm) Sacc. & Trotter, Syll. Fung. 22: 374. 1913. — Fig. 4f–s

≡ Anthostoma juglandinum Rehm, Ann. Mycol. 7: 531. 1909.

= Anthostoma juglandinum var. caryae Rehm, Ann. Mycol. 7: 531. 1909.

= Lopadostoma juglandinum var. caryae (Rehm) Sacc. & Trotter, Syll. Fung. (Abellini) 22: 375. 1913.

Holotype of Lopadostoma juglandinum. USA, Illinois, Port Byron, on hickory (Carya alba), 23 May 1904, E.T. & S.A. Harper No 1079 (C0004151F; as Anthostoma juglandinum, in F). Lectotype of L. juglandinum var. caryae, selected here: USA, Illinois, River Forest, on Carya alba, 20 Mar. 1909, E.T. & S.A. Harper (C0004152F; as A. juglandinum var. caryae No 2390 in F: MBT175916; isolectotypes in M, NY and Kew (K(M) 177255)).

Ectostromatic discs extremely variable, either separate and more or less circular (0.3–)0.5–1.5 mm diam, or more commonly ill-defined, arranged in more or less linear rows to forming a continuum several (e.g. 4) cm long and up to 3 mm broad, often fused, cracked into smaller, ill-defined pieces without distinct separation, projecting from the bark surface to 0.5 mm (up to 1.7 mm in material named as var. caryae), dark brown, dark grey to black, sometimes pale brown, flat, convex or pulvinate, smooth or tubercular. Ostioles inconspicuous and umbilicate in the disc or shiny black and convex or sometimes discoid and grey, 100–200 μm diam. Stromata densely arranged, erumpent from bark, extensive, widely effused, several cm long, containing several to many perithecial clusters and ostiolar discs, 0.8–3.5(–4) mm high, encased by a black line, the latter lacking between perithecial clusters within the stroma. Entostroma light-coloured, tissue between ostiolar necks whitish to pale greyish brown, darker brown in var. caryae, tissue between and beneath perithecia pale brownish, whitish mottled, comprising white hyphae mixed with bark cells. Perithecia numerous, crowded, mostly monostichous, clustered in valsoid configuration, subglobose or flask-shaped, often laterally compressed, 0.4–0.9 mm high, 0.3–0.8 mm wide. Ostiolar necks 0.2–1 mm long, slightly converging upwards. Asci easily disintegrating in KOH mounts, cylindrical, spore part (49–)59–76(–86) × (5.7–)6.0–7.5(–9.0) μm (n = 40), containing 8 uniseriate, material named as often distinctly overlapping ascospores; apical apparatus short, semiglobose, 4.5–5.5 μm wide, 2.5–3 μm high, containing a refractive, amyloid, (1.6–)1.8–2.2(–2.3) μm wide and (0.4–)0.5–0.8(–1.0) μm high (n = 20) apical ring in broadly rounded apex, often obscured by the uppermost ascospore. Ascospores oblong or ellipsoid, sometimes slightly allantoid, (7.8–)9.0–11.8(–14.5) × (3.5–)4.0–4.7(–5.5) μm, l/w = (1.7–)2.0–2.8(–3.9) (n = 134), not compressed, dark brown, smooth, without dwarf cell, germ slit distinct, commonly visible within asci, straight to slightly sinuous, circumferential.

Distribution & Habitat — North America (Illinois, Maine), in corticated branches of Carya alba.

Other specimens examined. USA, Illinois, Glencoe, on bark of Carya alba, 17 Apr. 1909, E.T. & S.A. Harper (K(M) 177254; as A. juglandinum); Maine, Kittery Point, on hickory (Carya alba), 1 Sept. 1930, R. Thaxter, det. L.E. Wehmeyer 6174 (M; as A. juglandinum var. caryae).

Notes — This species is currently only known from old herbarium specimens. Stromata of L. juglandinum are L. gastrinum-like regarding the pale-coloured entostromatic tissues, but differ by their sizes and wide expansion with many perithecial clusters, which are not encased by black lines. This latter feature recalls L. quercicola, but stromata of the latter species are much smaller and occur in species of Quercus in Europe. Lopadostoma juglandinum var. caryae is a more massive form of L. juglandinum, and although the stroma between ostiolar necks is sometimes darker in that variety, there are no statistical differences in microscopic data between the two varieties. Therefore recognition of a distinct variety may not be justified.

Lopadostoma lechatii Jaklitsch, J. Fourn. & Voglmayr, sp. nov. — MycoBank MB803807; Fig. 10

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Fig. 10

Lopadostoma lechatii. a, b. Ectostromatic discs; c, d. transverse stroma sections (c. ostiolar level); e–h. vertical stroma sections; i–l. asci (l. in Lugol); m–o. apical ascus rings (n, o. in Lugol); p–r. ascospores showing germ slit; s. clear drops on the colony centre on MEA at 25 °C after 64 d (a, b, d, e, g, h: JF06079; c, f, i–s: LG22). — Scale bars: a, e, g = 1 mm; b–d, s = 0.5 mm; f, h = 0.8 mm; i, j, l, m = 7 μm; k = 10 μm; n–r = 5 μm.

Holotype. FRANCE, Poitou-Charentes, Deux Sèvres, Villiers en Bois, La Taillée, on corticated twig of Carpinus betulus, 11 Mar. 2012, C. Lechat CLL 12009 (WU 32058; ex-type culture CBS 133694 = LG22).

Etymology. Named in honour of the French collector and ascomycete connoisseur Christian Lechat.

Ectostromatic discs circular or elliptic in outline, black, often with flaps of periderm laterally adhering to it, 1–3.6 mm long, at times coalescent in small groups of 2–3, projecting up to 1.2 mm above the host surface, flat or slightly convex, smooth or roughened. Ostioles opening separately in the disc, umbilicate in the disc or slightly raised-discoid, typically inconspicuous. Stromata pustulate-erumpent from bark, scattered or densely crowded, rarely in contact, subglobose and 2.3–5.8 mm wide or pulvinate and 2–2.5 mm wide and 1–1.2 mm high, with flattened base, laterally delimited by a grey to black line; the latter 120–200 μm thick, irregular in outline, reaching to the wood surface and spreading over it between adjacent stromata or uniting several perithecial groups. Tissue between ostiolar necks whitish or yellowish, woody; tissue around and beneath perithecia yellowish to pale brown, composed of bark tissue mixed with white fungal tissue in variable proportions; bark often scarcely altered. Perithecia 12–25 per stroma, arranged in valsoid configuration, monostichous in smaller, polystichous in larger stromata, subglobose or flask-shaped, 0.4–0.8 mm diam, somewhat laterally compressed when crowded, with short to long ostiolar necks converging upward. Asci cylindrical, long-stipitate (stipe e.g. 45 μm long), spore part (63–)67–80(–85) × (5.0–)5.5–6.7(–7.5) μm (n = 30), with 8 uniseriate spores and flat apical ring (1.5–)1.6–2.0(–2.2) μm wide, (0.5–)0.8–1.1(–1.2) μm high (n = 31), refractive in KOH, dark blue in Lugol. Ascospores variable in shape, ellipsoid, oblong, cylindrical, angular, sometimes inequilateral, (7.5–)8.0–9.5(–11.0) × (3.0–)3.5–4.3(–4.5) μm, l/w = (1.8–)1.9–2.6(–3.3) (n = 30), blackish brown, greyish brown when young, smooth, slightly laterally compressed, with narrow sheath in asci, straight, circumferential germ slit on narrower side visible in water, becoming invisible in KOH and in Lugol.

Cultures — Colony radius at room temperature on MEA 6–9 mm after 35 d, 11–13 mm after 2 mo; growth rate enhanced by 1 % peptone; colony circular to irregularly lobate, becoming several mm thick in the colony centre, indistinctly zonate, margin thin, hyaline; surface white to pale brown; after 2 mo colony centre with black spots or pustules and clear, colourless, grey-olive or black drops to 1 mm diam, not containing conidia; reverse yellowish to dull pale to dull grey-brown (5CD3–5). Chlamydospores common, globose or subglobose, (4.5–)5.0–9.0(–11.5) μm diam (n = 30), thick-walled. Odour strong, unpleasant, varnish-like. Growth and colony on PDA similar to MEA.

Distribution & Habitat — Only known from Western France on Carpinus betulus.

Other selected specimens examined. FRANCE, Charente Maritime, La Villedieu, Forêt d’Aulnay, on corticated branch of Carpinus betulus, 28 Apr. 2006, J. Fournier JF 06077 (WU 32090); Deux Sèvres, Forêt de Chizé, carrefour de l’Empereur, on corticated branch of Carpinus betulus, 24 Apr. 2006, J. Fournier JF 06079 (WU 32089).

Notes — This species is well defined by its small, often angular ascospores and the slowest growth of all species recognised here. Ascospore size is similar to that of L. insulare, which occurs on species of Quercus on Mediterranean islands and has a dark entostroma. The whitish entostromatic tissue of L. lechatii recalls L. gastrinum, which has distinctly larger ascospores and faster growth. Lopadostoma lechatii is common on its host in the region, where the above collections were made.

Lopadostoma linospermum (Durieu & Mont.) Jaklitsch, J. Fourn. & Voglmayr, comb. nov. — MycoBank MB803808; Fig. 11

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Fig. 11

Lopadostoma linospermum. a–o. Sexual morph: a. panoramic view of ostiolar discs; b, c. ectostromatic discs; d. transverse stroma section; e, f. vertical stroma sections; g–j. asci (g. in Lugol); k–n. apical ring and ascospores (m, n. in Lugol); o. ascospore showing germ slit. — p–v. Cultures and asexual morph on PDA at 22–25 °C: p. colony (55 d); q. conidial drop (62 d); r–v. conidia (63 d) (a, d–f, h–j, l, m, o: LPL; c: lectotype PC0085766; g, k, n, p–v: LPL1). — Scale bars: a = 2.5 mm; b–f, q = 0.5 mm; g–j, s = 15 μm; k, l = 7 μm; m = 5 μm; n, o = 3 μm; p = 10 mm; r, t–v = 10 μm.

Basionym. Sphaeria linosperma Durieu & Mont. in Durieu de Maisonneuve, Expl. Sci. Algerie 1: 467. 1846.

= Diatrype linosperma (Durieu & Mont.) Mont., Syll. Gen. Sp. Crypt.: 217. 1856.

= Anthostoma linospermum (Durieu & Mont.) Sacc., Syll. Fung. 1: 305. 1882.

Typification. The type folder of Sphaeria linosperma Durieu & Mont. in PC consists of three specimens, with the following information: ALGERIA, in bark of Pistacia lentiscus, C. Montagne: Durieu (Mostaganem, in cortice Lentisci), without collection dates; PC0085766 (= MC8671; MBT175917), the best preserved specimen is here selected as the lectotype of Sphaeria linosperma. PC0085764 (= MC8670) and PC0085765 (= MC8669 = MS4242599) are isolectotypes. Epitype here designated: ITALY, Sardinia, Oliena, near the hotel Su Gologone, on branch of Pistacia lentiscus, 3 Nov. 2009, W. Jaklitsch (WU 32059; MBT175918; ex-epitype culture CBS 133208 = LPL).

Ectostromatic discs circular, oblong or elliptic in outline, 0.7–2.7 mm in their greatest dimension, brown or blackish, projecting up to 1.2 mm above the host surface, flat, convex or pulvinate, shiny in places. Ostioles opening separately in the disc, umbilicate, inconspicuous, less commonly distinct, convex to papillate, black, shiny, 100–300 μm diam. Stromata pustulate, immersed to slightly erumpent, scattered, separate or coalescent in groups of 2–5, subglobose, 2–4 mm diam, surrounded by a black stromatic line; the latter irregular in outline, reaching the wood surface and spreading over it between adjacent stromata. Tissue between the ostiolar necks olivaceous yellow, prosenchymatous, abundant and conspicuous, not yielding a pigment in 10 % KOH, soft-textured, extending downwards between the perithecia, turning whitish and progressively merging with the basal tissue which is composed of slightly bleached bark tissue. Perithecia 4–20 per stroma, in valsoid configuration, monostichous in smaller stromata, polystichous in larger ones, ovoid to obpyriform, often laterally compressed, 0.7–1 mm high, 0.5–0.85 mm wide, with long ostiolar necks converging toward the disc. Asci cylindrical, containing (4–)8 uniseriate, partly overlapping ascospores, spore-bearing part (96–)107–127(–145) × (6.3–)6.8–8.5(–9.5) μm (n = 45); apical ring flat, refractive, amyloid, (1.6–)2.0–2.4(–2.6) μm wide, (0.5–)0.6–1.1(–1.2) μm high (n = 33). Ascospores oblong to nearly cylindrical, (12.2–)13.5–17.3(–20.3) × (4.0–)5.0–6.2(–7.5) μm, l/w (2.0–)2.4–3.2(–4.0) (n = 112), often longest in basal position, not or slightly compressed, unicellular, blackish brown, smooth, with a straight, circumferential, spore-length germ slit.

Cultures and asexual morph — Ascospores germinating on MEA after 4–5 d; colony radius at room temperature on MEA 15–20 mm after 35 d; colony circular, surface covered by a cottony white mat of aerial hyphae, margin turning brown, brown pigment diffusing into the agar, reverse pale yellowish to brownish. Conidia forming after 1.5 mo in the colony centre in 1–1.6 mm long, subhyaline, dull yellowish to pale brownish, mucous conidial pustules on 1–3 μm wide, smooth or warted conidiophores. Conidia (16–)20–25(–27) × (1.3–)1.4–1.6(–1.8) μm, l/w (10.8–)12.5–17.4(–19.1) (n = 30), hyaline, falcate, 1-celled, smooth, strongly curved to semicircular, with a long, nearly straight, narrowly truncate end and a short, strongly curved, acute end. Colony on PDA as on MEA, but darker and whitish/brownish zonate, conidia forming in colourless to pale yellowish drops in the colony centre.

Distribution & Habitat — Europe and North Africa, on corticated branches of Pistacia lentiscus in the Mediterranean region.

Other specimens examined. SPAIN, Andalucia, Alcalá de los Gazules, Santuario de Nuestra Senora de los Santos, N36°26’58", W5°46’16.5", on branch of Pistacia lentiscus, 17 Mar. 2011, W. Jaklitsch & H. Voglmayr (WU 32061; culture LPL2); Andalucia, road A2226 to Benalup, at km 10, on branches of Pistacia lentiscus, 18 Mar. 2011, W. Jaklitsch (WU 32060; culture LPL1). Without geographic data, no collection date, on bark of Pistacia lentiscus, D.S. Corell, ex herb. M.J. Berkeley (K(M) 177258).

Notes — Lopadostoma linospermum is the counterpart of L. dryophilum on Pistacia lentiscus, based on ascospore characteristics and the yellow-olivaceous interostiolar stromatic tissue. However, apart from the different host it also forms an asexual morph in contrast to L. dryophilum. At first sight stromata of L. linospermum often resemble those of a Diatrypella.

Lopadostoma meridionale Jaklitsch, J. Fourn. & Voglmayr, sp. nov. — MycoBank MB803809; Fig. 12

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Fig. 12

Lopadostoma meridionale. a–p. Sexual morph: a, b. panoramic view of ectostromatic discs; c. ectostromatic discs; d, e. transverse stroma sections (d. ostiolar level); f, g. vertical stroma sections; h–k. asci (j, k. in Lugol); l–n. apical rings (m, n. in Lugol); o, p. ascospores showing germ slit. — q–u. Asexual morph on MEA at 25 °C after 48 d: q, r. conidial drops; s–u. conidia (a, c, d, h, j, l, m, o: LG29; b, e–g: LG10; i, k, n, p–u: LG). — Scale bars: a, b = 1 mm; c, d = 0.4 mm; e–g = 0.7 mm; h–k, s = 10 μm; l–p, u = 5 μm; q, r = 0.5 mm; t = 7 μm.

Holotype. CROATIA, Istrija, Barbariga, forest N of the village, elev. c. 20 m, on a branch of Quercus ilex, 24 Sept. 2010, W. Jaklitsch (WU 32062; ex-type culture CBS 133209 = LG).

Etymology. Meridionale means southern; owing to its primarily southern distribution in Europe.

Ectostromatic discs circular or ellipsoid, 0.7–2.3 mm in their greatest dimension, projecting 0.3–0.7 mm above the often darkened, grey or brown host surface, pulvinate, convex or flat, often irregularly roughened or tubercular, shiny in places. Ostioles opening separately in the disc, umbilicate, inconspicuous. Stromata pustulate, scattered, separate or coalescent in groups of 2–6, subglobose, 1.8–4 mm diam, immersed in bark tissue, erumpent, surrounded by a black carbonised stromatic line 80–120 μm thick, irregular in outline, usually constricted beneath the stroma, reaching the wood surface and spreading over it between adjacent stromata. Tissue between ostiolar necks black, woody, not extending downwards between the perithecia, the tissue below the perithecia dull brownish with whitish spots, composed of slightly bleached bark tissue and whitish hyphae. Perithecia 3–10 per stroma, arranged in valsoid configuration, monostichous in smaller stromata, polystichous in larger ones, ovoid, obpyriform or flask-shaped, often laterally compressed, 0.8–1 mm high and 0.7–1.2 mm wide, with long ostiolar necks converging toward the disc. Asci cylindrical, spore part (68–)74–95(–113) × (6.2–)6.5–7.5(–8.5) μm (n = 60), containing 8 uniseriate ascospores, stipe c. 50 μm long; apex thickened, with a flat subapical, refractive, amyloid ring (1.8–)1.9–2.2(–2.4) μm wide, (0.5–)0.7–1.0(–1.2) μm high (n = 40). Ascospores oblong or narrowly ellipsoid, sometimes reniform or banana-shaped, (8.7–)10.3–12.8(–14.8) × (3.5–)4.0–4.8(–5.5) μm, l/w = (1.6–)2.3–3.1(–3.8) (n = 135), not distinctly compressed, first hyaline, turning yellow-brown and eventually dark brown, smooth, with 1–2(–3) guttules and inconspicuous, narrow, straight, circumferential germ slit, with thin sheath on one side in the ascus, dwarf cell lacking.

Cultures and asexual morph — Growth highly variable among strains (n = 7) but also within a single isolate, colony radius at room temperature on MEA 15–30 mm after 35 d, sometimes growth stopping after reaching a colony radius of 10–15 mm, remaining yellowish or turning brownish. Colony circular, thin or surface covered with a thick, cottony, white, radially structured mat of aerial hyphae or tufts along the margin, first white, turning yellowish or brownish, sometimes with a faintly rosy tint, sometimes zonate; reverse yellowish or dull yellow, turning brown in the centre, sometimes developing brown to black spots, accompanied by the formation of a diffusing reddish brown pigment. Odour either unpleasant and ‘chemical’ or more or less fruity. After 1.5 mo conidia forming in mucous, yellow to orange, brown to black drops or pustules. Conidia falcate, (19–)22–27(–30) × (1.2–)1.3–1.5(–1.7) μm, l/w = (11.9–)14.8–20.1(–22.5) (n = 30), hyaline, 1-celled, strongly curved to nearly circular, with truncate base and acute end, smooth. On PDA growth sometimes distinctly faster than on MEA and colony covering a 90 mm Petri dish in 4.5 mo at room temperature, sometimes colony distinctly yellow.

Distribution & Habitat — Europe, on corticated branches of Quercus coccifera and Q. ilex; widely distributed, particularly in the Mediterranean region.

Other specimens examined. CROATIA, Istrija, Rovinj, holm oak wood NW Monsena, on a branch of Quercus ilex, 17 May 2012, H. Voglmayr (WU 32068; culture LG36); Ugljan, northern tip of the island, on branch of Quercus ilex, 8 Aug. 1996, W. Jaklitsch W.J. 906 (WU 32103). – FRANCE, Ardéche, Vallon Pont d’Arc, banks of the river Ardéche, on branch of Quercus ilex, 2 May 2012, J. Fournier JF 12070 (WU 32069; culture LG40); Charente Maritime, Ile de Ré, Saint Martin en Ré, on a branch of Quercus ilex, 26 Apr. 2006, J. Fournier JF 06087 (WU 32063; culture LG10). – GREECE, Corfu, Agia Anna, on branch of Quercus coccifera, 23 Apr. 2012, H. Voglmayr & W. Jaklitsch (WU 32065; culture LG33); Kanakades, on branch of Quercus ilex, 20 Apr. 2012, H. Voglmayr & W. Jaklitsch (WU 32064; culture LG29); Prinilas, shortly after Vistonas above Prinilas, on branch of Quercus coccifera, 23 Apr. 2012, H. Voglmayr & W. Jaklitsch (WU 32066; culture LG34); Prinilas, white road to the left before entering Prinilas, on branch of Quercus ilex, 23 Apr. 2012, W. Jaklitsch & H. Voglmayr (WU 32067; culture LG35).

Notes — Morphologically, L. meridionale is characterised by rather small, irregular ectostromatic discs, well-developed dark brown to black tissue between the ostiolar necks and intermediate ascospore size between L. insulare and L. dryophilum. Lopadostoma quercicola has similar ascospores, but occurs on different species of Quercus. Lopadostoma meridionale is so far the only species of the genus on Quercus in Europe that yielded an asexual morph on MEA. However, the asexual morph has not been seen in all strains. The data given by Ju et al. (1993; as L. turgidum) for the asexual morph obtained with an isolate from French material on Quercus ilex suggest that they studied L. meridionale.

In some isolates early termination of growth was observed, which seems to be correlated with the formation of a diffusing pigment and strong unpleasant odour and therefore might be a consequence of self-intoxication. Such results were more pronounced in strains of L. quercicola.

Lopadostoma quercicola Jaklitsch, J. Fourn. & Voglmayr, sp. nov. — MycoBank MB803810; Fig. 13

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Fig. 13

Lopadostoma quercicola. a, b. Stroma surface; c–e. ectostromatic discs; f–h. transverse stroma sections (f. ostiolar level); i–k. vertical stroma sections; l–o. asci; p–r. apical ascus rings (q, r. in Lugol); s–u. ascospores showing germ slit (u. compressed, showing slit on both sides) (a, k: LG17; b, d, l, m, r, u: LG12; c, h, j, o, t: LG27; e, f, i, q, s: LG3; g, n: LG25; p: LG38). — Scale bars: a = 2 mm; b = 1.5 mm; c–e = 0.3 mm; f–k = 0.6 mm; l–p = 10 μm; q, u = 7 μm; r–t = 5 μm.

Holotype. AUSTRIA, Niederösterreich, Pfaffstätten, on Quercus pubescens, 15 Apr. 2012, H. Voglmayr (WU 32079; ex-type culture CBS 134633 = LG27).

Etymology. Occurring on Quercus.

Ectostromatic discs separate or clustered in small groups of 2–3 or more or in more or less long rows at the bottom of cracks in thick bark, grey or black, usually not surrounded by ruptured periderm, circular or elliptic in outline, 0.4–2 mm in their greatest dimension, flush with the surface or distinctly convex-pulvinate, projecting up to 0.8 mm above the bark surface, smooth to roughened. Ostioles opening separately in the disc, inconspicuous and umbilicate or more commonly distinct, flat and shiny or rounded-papillate, 70–240 μm wide, rarely distinctly projecting and stout. Stromata pustulate, often pulvinate and widely erumpent, often gregarious, usually containing several perithecial groups; the latter subglobose, usually not delimited by a black stromatic line, the latter only present around the entire stroma and running between bark and wood. Tissue between ostiolar necks brown, dark grey to blackish, woody, extending downwards between perithecia; tissue around and beneath perithecia composed of hardly altered, slightly bleached bark tissue and whitish spots of fungal mycelium. Perithecia 4–16 per stroma, arranged in valsoid configuration, usually monostichous, rarely polystichous in larger groups, subglobose or flask-shaped, 0.4–1 mm diam, somewhat laterally compressed when crowded, with short to long ostiolar necks converging toward the disc. Asci cylindrical with stipes to c. 50 μm long, spore part (66–)72–91(–108) × (4.3–)5.8–7.3(–8.5) μm (n = 60), containing 8 more or less uniseriate, often overlapping ascospores and a refractive, amyloid, (1.5–)1.8–2.0(–2.2) μm wide and (0.5–)0.6–0.8(–1.0) μm high (n = 33) ring in a subglobose apical apparatus. Ascospores oblong or narrowly ellipsoid, (8.7–)9.5–12.0(–14.3) × (3.8–)4.3–5.0(–5.5) μm, l/w = (1.8–)2.1–2.7(–3.2) (n = 140), longest in basal position, not compressed, first hyaline, then smoky grey-brown, with 1–2 large guttules, eventually dark, chocolate to blackish brown, smooth, with a narrow hyaline perispore 0.5 μm thick visible on one side in asci, with a straight or slightly sinuous, circumferential germ slit.

Cultures — Colony radius at room temperature on MEA 11–19 mm after 35 d, 22–28 mm after 2 mo. Colony circular, thin and smooth, sometimes with radial folds, surface and reverse (pale) yellow, e.g. 4A3–4, sometimes with a rosy tint, aerial hyphae scant or lacking; odour unpleasant, strong, varnish-like, also when colony yellow and no diffusing pigment is formed. No asexual morph formed on MEA within 6 mo. Colony sometimes remaining small with a radius of 10–13(–17) mm, turning grey or greyish brown, reverse turning brown to black and brown pigment diffusing in the agar. Growth and colony on PDA similar to MEA.

Distribution & Habitat — Europe, in corticated branches of Quercus cerris, Q. petraea, Q. pubescens and Q. suber, possibly also Q. robur; widely distributed, particularly common around Vienna, Austria.

Other specimens examined (all on corticated branches). AUSTRIA, Niederösterreich, Gießhübl, on Quercus petraea, 18 Mar. 2012, H. Voglmayr (WU 32077; culture LG19); Heiligenkreuz, close to the highway exit, on Quercus cerris, 16 Mar. 2012, H. Voglmayr & W. Jaklitsch (WU 32075; culture LG16); ibid., on Quercus petraea, 16 Mar. 2012, H. Voglmayr & W. Jaklitsch (WU 32076; culture LG17); Siegenfeld, shortly after the village heading to Gaaden, on a corticated branch of Quercus cerris, 16 Mar. 2012, W. Jaklitsch & H. Voglmayr (WU 32072; culture CBS 133212 = LG12); ibid., on Quercus petraea, 16 Mar. 2012, H. Voglmayr & W. Jaklitsch (WU 32073; culture LG14); ibid., on Quercus cerris, 16 Mar. 2012, H. Voglmayr & W. Jaklitsch (WU 32074; culture LG15); Waxeneck, NE Pernitz, near Schutzhaus, on Quercus petraea, 9 June 2013, H. Voglmayr & I. Greilhuber (LI); Vienna, 19th district, Hermannskogel, grid square 7763/2, on branch of Quercus cerris, 11 Feb. 1995, W. Jaklitsch W.J. 489 (WU 32104); ibid., on Quercus cerris, 19 Aug. 1995, W. Jaklitsch W.J. 710 (WU 32105); ibid., on Quercus cerris, 27 Mar. 1999, W. Jaklitsch W.J. 1294 (WU 32107); Vogelsangberg, on Quercus cerris, 3 Mar. 2012, W. Jaklitsch & H. Voglmayr (WU 32071; culture LG9); 23rd district, Maurer Wald, grid square 7863/1, on Quercus cerris, 19 Oct. 1996, W. Jaklitsch W.J. 987 (WU 32106). – CROATIA, Istrija, Rovinj, at the road Rovinj-Bale, c. 2 km W Bale, on Quercus cerris, 18 May 2012, H. Voglmayr (WU 32080; culture LG37); Rovinj, field edge N of the nature preserve Palud, on Quercus pubescens, 19 May 2012, H. Voglmayr (WU 32081; culture LG38); Vižinada, NW Žudetići, at the road to Ponte Porton, on Quercus cerris, 20 May 2012, H. Voglmayr (WU 32082; culture LG39). – FRANCE, Côte d’Or, forêt de Longchamp, near Maison Forestière du Tertre, elev. 240 m, on Quercus sp. (Q. petraea or Q. robur), 13 Oct. 2005, P. Leroy PL05414D; Indre et Loire, Bois de Roche-Monts, on Quercus sp. (Q. petraea or Q. robur), 30 May 2006, P. Leroy PL06222C (WU 32078; culture LG25); Loir et Cher, Boulogne, carrefour du roi de Pologne, on Quercus sp. (Q. petraea or Q. robur), 22 Oct. 2004, P. Leroy PL04435A. – ITALY, Sardinia, Aggius, on branch of Quercus suber, 7 Nov. 2009, W. Jaklitsch (WU 32070; culture LG3). – PORTUGAL, Oeiras, on branch of Quercus suber, Nov. 1978, A.M. Macava (WU 32094).

Notes — Lopadostoma quercicola is one of the five species recognised here on Quercus. Stromata of this species are often widely erumpent and contain many perithecial groups, similar to L. juglandinum. The black stromatic line is often invisible, because it only surrounds the whole stroma, not the individual perithecial groups within the stroma. Lopadostoma americanum differs from L. quercicola by its occurrence on white oaks in North America, ill-defined ectostromatic discs, slightly wider ascospores, faster growth and formation of an asexual morph; L. insulare by distinctly smaller ascospores and occurrence on the evergreen oaks Quercus coccifera and Q. ilex on Mediterranean islands; L. meridionale by occurrence on the evergreen oaks Quercus coccifera and Q. ilex and formation of an asexual morph; and L. dryophilum differs by larger ascospores and a yellow-olivaceous entostroma between the ostioles.

Frequently slow and early terminated growth of several strains is correlated with a discolouration of the colony to grey-brown and black on the reverse and by diffusion of a grey- to dark brown pigment into the agar. Such cultures can often be revived by transfer to fresh medium. The strong, varnish-like odour is also formed when the colony is yellow and fast-growing and no diffusing pigment is formed. In L. meridionale the diffusing pigment occurs less commonly and is more reddish brown.

Lopadostoma turgidum (Pers.) Traverso, Fl. Ital. Crypt. 1, 1, 2: 170. 1906. — Fig. 14

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Fig. 14

Lopadostoma turgidum. a–n. Sexual morph: a. panoramic view of stromata; b. two stromata in face view; c. ectostromatic disc; d. transverse stroma section; e, f. vertical stroma sections; g–i. apical ring and ascospores (h, i. in Lugol); j. ascospore showing germ slit; k–n. asci. — o–v. Cultures and asexual morph: o. colony with asexual morph; p, r, s. conidiophores (p. showing phialide bearing conidium); q. pycnidia; t–v. conidia (o–v: all on MEA at 25 °C after 70–74 d. a, c–f: LT; b, j, k, n, o, q, u: LT2; g–i, l, m, p, r–t, v: LT1). — Scale bars: a = 1.5 mm; b = 0.7 mm; c–f = 0.3 mm; g–i, u = 7 μm; j = 3 μm; k, r–t = 15 μm; l–n, p, v = 10 μm; q = 1 mm.

Typification. From the two original specimens of Persoon present in L, L0108269 and L0108272 (no collection data given), L0108272 (MBT175919) is here selected as lectotype of Sphaeria turgida. Epitype here designated: AUSTRIA, Niederösterreich, Gaaden, 3 Dec. 2011, H. Voglmayr (WU 32085; ex-epitype culture CBS 133207 = LT2; MBT175920).

Basionym. Sphaeria turgida Pers., Observ. Mycol. (Lipsiae) 1: 17. 1796.

= Anthostoma turgidum (Pers.) Nitschke, Pyrenomycetes Germanici 1: 121. 1867.

Stromata widely effused on recently dead branches, up to 30–40 cm long, uniting numerous small, typically densely gregarious, separate or coalescent, flattened pustules 1–2 mm diam, slightly raising the periderm and discolouring it dark silvery grey above the pustules, contrasting with the surrounding reddish brown colour; perithecial mounds at the pustule margin often distinct. Centre of pustules pierced by a dark grey to black ectostromatic disc (0.20–)0.25–0.45(–0.55) mm diam (av. = 0.3 mm, n = 110), circular or elliptic in outline, flat, slightly convex or concave, flush with the bark surface or more rarely projecting 40–170 μm above it, surrounded by teeth-like remnants of the ruptured bark. The tissue between the ostioles and above the perithecia blackish, soft-textured, the tissue surrounding perithecia somewhat powdery, composed of white fungal tissue mixed with yellowish brown bark cells; the tissue beneath perithecia more solid, composed of hardly decayed host tissue delimited in the lower part by a thin, often inconspicuous dark brown to black stromatic line; loosening bark below stromata seated on a thick dark brown felty layer spreading over the wood surface. Perithecia 3–8(–10) per stroma, monostichous, circinate, densely aggregated, subglobose to depressed-globose, (0.45–)0.5–0.7(–1.1) mm diam, with long ostiolar necks converging toward the disc, opening separately in the disc. Ostioles umbilicate, inconspicuous or invisible. Asci cylindrical, long stipitate (e.g. stipe 55 μm long), containing 8 uniseriate ascospores, spore-bearing part (72–)94–112(–119) × (6.5–)7.0–8.3(–8.7) μm (n = 51), amyloid ring (2.0–)2.2–2.5(–2.7) μm wide, (0.3–)0.5–0.8(–0.9) μm high (n = 15). Ascospores ellipsoid, (8.5–)10.2–12.2(–13.7) × (5.0–)5.5–6.0(–6.5) μm, l/w (1.5–)1.7–2.1(–2.5) (n = 94), dark brown to nearly black, opaque when mature, smooth, with straight spore-length germ slit on one side only, and 2 large guttules when young; lowest ascospore in the ascus often longer than others.

Cultures and asexual morph — Ascospores germinating on MEA after 2–3 d; colony radius at room temperature on MEA 17–18 mm after 35 d, 35–37 mm after 4.5 mo. Colony circular with well-defined margin, white, turning brown from the centre; reverse turning dark brown with orange-brown margin, yellow-brown pigment diffusing into the agar; odour indistinct. Cream, pale yellow to orange mucous masses of conidia forming after 1.5–2 mo in effuse spots or well-defined pycnidia c. 1 mm diam. Conidiophores simple, formed in white floccules on a wide moniliform, thick-walled stipe to 9.5 μm wide, asymmetrically branched in narrow angles into verticils of terminal branches 1–3.5 μm wide, bearing long cylindrical to subulate, straight or curved phialides singly or in whorls of 2–6. Conidia falcate, (15–)20–26(–31) × (1.3–)1.5–1.7(–1.9) μm, l/w (8.8–)12.2–17.4(–20.3) (n = 63), hyaline, 1-celled, smooth, upper end nearly acute, base truncate, slightly to distinctly curved, with minute guttules. On PDA similar to MEA, but lighter coloured, brownish with hyaline or white margin; conidia forming in orange-brown drops.

Distribution & Habitat — Europe, in corticated branches of Fagus sylvatica; common.

Additional specimens and records, all from corticated branches of Fagus sylvatica. AUSTRIA, Kärnten, St. Margareten im Rosental, Stariwald, elev. 600 m, grid square 9452/4, 27 Dec. 1994, W. Jaklitsch W.J. 402 (WU 32108); ibid., 11 July 2011, W. Jaklitsch (WU 32083; culture LT); ibid., Zabrde, 12 Aug. 1995, W. Jaklitsch; Rechberg, grid square 9453/3, 6 Sept. 1998, W. Jaklitsch; Niederösterreich, Hainbuch, grid square 7763/1, 28 Sept. 1996, W. Jaklitsch; Lahnsattel, virgin forest Neuwald, from Donaudörfl, grid square 8259/1, 31 July 1999, W. Jaklitsch; Lunz am See, Rothwald 2, grid square 8256/2, 3 July 1999, W. Jaklitsch; Mauerbach, 31 July 2011, W. Jaklitsch (WU 32084; culture LT1); Ottenstein, Dobra-Stausee: virgin forest at the dam, grid square 7458/1, 28 Sept. 2003, W. Jaklitsch; Steiermark, Berghausen, Graßnitzberg, grid square 9259/4, 20 Sept. 1996, W. Jaklitsch; Pöllau, Schönauklamm, grid square 8760/2, 12 Sept. 2002, W. Jaklitsch; Tirol, Tristach, Buchwiese, grid square 9142/4, 30 Aug. 2000, W. Jaklitsch; Vienna, 19th district, Kahlenberg, grid square 7763/2, 15 Dec. 1996, W. Jaklitsch; Cobenzl, grid square 7763/2, 5 July 1998, W. Jaklitsch W.J. 1172 (WU 32109); 23rd district, Maurer Wald, grid square 7863/1, 3 Oct. 1998, W. Jaklitsch. – FRANCE, Ariege, Prat-Communal, Loumet, elev. 900–950 m, 21 Apr. 2012, J. Fournier JF 12051; Rimont, Las Muros, Grand Bois, combe Fourcade, elev. 750 m, 9 Nov. 2011, J. Fournier JF 11165 (WU 32086; culture LT3); Hautes Pyrénées, Castillon, Moulin de Sarthe, elev. 360 m, 9 Apr. 2011, J. Fournier JF 11030. Numerous additional records from Austria, Czech Republic, Denmark, Germany, The Netherlands, United Kingdom, based on gross morphology, i.e. distinction from L. fagi uncertain.

Notes — Lopadostoma turgidum is common on Fagus in Europe, but is at times locally nearly entirely replaced by L. fagi, which differs in slightly larger ectostromatic discs (0.5 vs 0.3 mm in average), smaller ascospores, a circumferential germ slit and different culture characteristics like rosy colony reverse and faster growth. Stromata of both species differ from those of other species in that they are more valsoid than diatrypelloid, with little stromatic tissue present below the perithecia.

At first sight L. turgidum and L. fagi may be easily confounded with Quaternaria quaternata, which is extremely common on Fagus and often co-occurs with them. The latter can, however, be distinguished under a lens by its distinct ostioles that are not embedded in a compact disc.

A specimen from New York (Renssalaer Co., Taborville, Cherry Brook Recreation Area, 10 Sept. 1977, M.E. Barr Bigelow 6409 (NY)) on Fagus grandifolia has extremely small stromata with only the minute black discs visible, but otherwise unchanged bark surface. Ascospores, however, are in agreement with L. turgidum. Proof of conspecificity would require fresh material and gene sequences.

The lectotypification of L. turgidum by Lu & Hyde (2000) is invalid, because they selected material collected by C. Montagne, which was not part of Persoon’s original material. They, however, correctly noted that L. turgidum is type of the genus, examined also the two original specimens of Persoon and gave a description, which matches our findings.

EVALUATION OF TAXA IN LOPADOSTOMA, ANTHOSTOMA AND PHAEOSPERMA

Including infraspecific taxa, there are at least 183 combinations in Anthostoma (21 missing in Index Fungorum and MycoBank), 31 in Lopadostoma and 18 in Phaeosperma. Many names have been removed from these genera to others such as Amphisphaerella, Anthostomella, Apiorhynchostoma, Barrmaelia, Biscogniauxia, Camarops, Capronia, Coniochaeta, Cryptosphaeria, Didymella, Dyrithium, Endoxyla, Entoleuca, Eutypa, Gigantospora, Helicogermslita, Hypoxylon, Immotthia, Jumillera, Lepteutypa, Leptomassaria, Loculohypoxylon, Pseudovalsaria, Quaternaria, Rosellinia, Splanchnonema, Whalleya and Xylomelasma.

All names in Lopadostoma and some names in Anthostoma, which are not treated above and initially thought to be relevant in this context, are commented on below. Relevant names in Phaeosperma are included as synonyms of species treated under the accepted species above or in the commentary below.

1) Names in Lopadostoma

Lopadostoma amoenum (Nitschke) Shear, Mycologia 30, 5: 593. 1938. — Fig. 15a–h

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Fig. 15

a–h. ‘Lopadostoma’ cf. amoenum (JF 08072). a. Habit; b, c. ectostromatic discs with ostioles; d. vertical stroma section; e. apical ascus ring in Lugol; f, g. ascospores; h. asci in Lugol. — i–m. Anthostoma gastrinoides (holotype K(M) 177256). i. Cut perithecium with gelatinous contents; j. ascospores; k–m. asci (m. in Lugol). — n–t. Anthostoma insidiosum (Valsa insidiosa holotype; CO). n, o. Ectostromatic discs with ostioles; p. vertical stroma section; q–s. apical ascus rings (q, s. in Lugol); t. ascospores. — Scale bars: a = 1 mm; b–d, i, p = 0.3 mm; e, g, j = 7 μm; f, r, s = 10 μm; h, q = 25 μm; k–m, t = 15 μm; n, o = 0.2 mm.

≡ Fuckelia amoena Nitschke, Jahrb. Nassauischen Vereins Naturk. 23–24: 224. 1870 (1869–1870).

= Anthostoma amoenum (Nitschke) Sacc., Syll. Fung. (Abellini) 1: 307. 1882.

A recent collection from France, Deux Sèvres, Villiers en Bois, Forêt de Chizé, Rimbaud, on dead twig of Fagus sylvatica, 14 Apr. 2008, P. Leroy (JF 08072; culture MUCL 51842 = LA; kindly provided by M. Stadler) was studied:

Stromata immersed in bark, scattered, pustulate, erumpent, 0.4–1 mm diam, appearing on the bark surface as small white to yellowish granular ectostromatic discs containing 1–5 convergent but separately opening ostioles; the latter 100–160 μm wide, smooth, black, rounded at the top, flush with the stromatal surface to slightly projecting. Perithecia arranged in valsoid configuration, subglobose with flattened base to lenticular, 0.4–0.5 mm wide, 0.2–0.3 mm high, surrounded by decayed cortical tissue; black stromatic line absent. Ostiolar necks central or more commonly eccentric and oblique. Paraphyses simple, abundant. Asci cylindrical, with 8 uniseriate ascospores, short-stipitate, 140–160 μm long, with a massive, diamond-shaped, 6.5–7.5 μm wide and 2.5–4 μm high, apparently bipartite, amyloid apical ring, with the lower part stronger bluing in iodine than the upper. Ascospores broadly ellipsoid with narrowly rounded ends to citriform, (18.5–)20.8–24.0(–25.7) × (10.2–)11.5–13.2(–14.7) μm, l/w = (1.5–)1.6–2.0(–2.5) (n = 34), 1-celled, equilateral, olive-brown, smooth, with a central to eccentric, rounded and 2.5–3 μm wide germ pore and bipolar cellular appendages 1 μm thick and 3 μm broad; contents with numerous large and small guttules.

Notes — This specimen is in agreement with the description of Fuckelia amoena by Læssøe & Spooner (1994) except for slightly smaller ascospores. Læssøe & Spooner (1994) studied two isotypes (K) and discussed similarities to and differences from Lopadostoma and Euepixylon. The latter shares the poroid germ locus with L. amoenum. Apart from morphology, also an LSU sequence obtained from the above specimen places the fungus outside Lopadostoma. The genus Fuckelia Nitschke is a later homonym of Fuckelia Bonord. 1864 and therefore unavailable.

Lopadostoma apiculatum (Sacc.) P.M.D. Martin, J. S. African Bot. 42, 1: 75. 1976.

Basionym. Sphaeria apiculata Curr., Trans. Linn. Soc. London 22: 326. 1859 (non Sphaeria apiculata Wallr., Fl. Crypt. Germ. (Norimbergae) 2: 778. 1833).

= Phaeosperma apiculatum (Curr.) Sacc. & Traverso, Syll. Fung. 20: 326. 1911.

Current name — Apiorhynchostoma curreyi fide Petrak (1923; as A. apiculata) or Müller & von Arx (1962).

Lopadostoma caespitosum (Ellis & Everh.) P.M.D. Martin, J. S. African Bot. 42, 1: 75. 1976.

Basionym. Rosellinia caespitosa Ellis & Everh., Proc. Acad. Nat. Sci. Philadelphia 46: 327. 1894.

This is a Coniochaeta sp. fide Barr et al. (1996).

Lopadostoma conorum (Fuckel) P.M.D. Martin, J. S. African Bot. 42, 1: 75. 1976.

Basionym. Amphisphaeria conorum Fuckel, Jahrb. Nassauischen Vereins Naturk. 29–30: 20. 1875 (1877).

= Anthostoma conorum (Fuckel) Cooke, Grevillea 17: 90. 1889.

Current name — Anthostomella conorum (Fuckel) Sacc. fide Francis (1975) and Lu & Hyde (2000).

Lopadostoma cubiculare (Fr.) P.M.D. Martin, J. S. African Bot. 42, 1: 75. 1976.

Basionym. Sphaeria cubicularis Fr., Syst. Mycol. (Lundae) 2, 2: 477. 1823.

= Anthostoma cubiculare (Fr.) Nitschke, Pyrenomycetes Germanici 1: 113. 1867.

Current name — Helicogermslita fleischhakii fide Læssøe & Spooner (1994) and Rappaz (1995).

Lopadostoma dubium (Feltgen) Sacc. & Trotter, Syll. Fung. 22: 375. 1913.

Basionym. Anthostoma dubium Feltgen, Vorstud. Pilzfl. Luxemb., Nachtr. II: 111. 1901.

Described from Luxembourg on Corylus avellana as forming valsoid perithecia and ascospores 12–15 × 4–6 μm. No material bearing this name was received from B, BR, K or LUX, therefore its identity remains unclear and doubtful.

Lopadostoma flavoviride (Ellis & Holw.) Rappaz, Mycol. helv. 7, 1: 129. 1995.

Basionym. Anthostoma flavoviride Ellis & Holw., in Arthur et al., Bull. Geol. Nat. Hist. Surv. 3: 32. 1887.

Stromata in wood, effuse. Not a species of Lopadostoma s.str., but belonging to L. subg. Anthostomopsis, which may eventually be split into several genera.

Lopadostoma formosum (Ellis & Everh.) P.M.D. Martin, J. S. African Bot. 42, 1: 75. 1976.

Basionym. Anthostoma formosum Ellis & Everh., Proc. Acad. Nat. Sci. Philadelphia 46: 344. 1894.

The holotype, USA, Kansas, on dead limbs of Celtis occidentalis, 14 June 1894, Bartholomew No. 1492 (NY), was examined. The material is mostly depauperate, with partly disintegrated, black, convex or pulvinate discs 0.4–1.6 mm diam, with inconspicuous ostioles or irregular clusters of ostioles projecting up to 1 mm. Stromatic tissue within the black line is poorly developed and pale brownish. Asci cylindrical, spore part (72–)75–88(–92) × (6.0–)6.3–7.3(–7.5) μm (n = 10), containing 8 uniseriate ascospores and a flat refractive, amyloid ring. Ascospores oblong, (9.7–)10.0–11.8(–14.8) × (4.0–)4.3–5.2(–5.5) μm, l/w (1.9–)2.1–2.6(–3.0) (n = 30), dark brown, light when young, smooth, without dwarf cell, germ slit along narrower side, circumferential, straight. Morphologically, L. formosum is thus in agreement with L. gastrinum, as indicated by Rappaz (1995 and on the label of the holotype).

Lopadostoma gallicum Sacc., Atti Mem. Accad. Sci. Lett. Arti, Padova 33: 159. 1917.

The holotype was examined in PAD: Stromata are immersed in bark of Acer pseudoplatanus, irregularly distributed or aggregated in lines. Internally they are white and surrounded by black lines. Ostioles slightly projecting and rounded or up to pentagonal in face view. The stromata are in accordance with those of L. gastrinum, but asci are long-stipitate, inamyloid and contain 8 ascospores in biseriate arrangement. Ascospores are allantoid, dark brown, measure (7.0–)7.8–10.5(–12.2) × (2.5–)2.7–3.3(–3.5) μm, l/w = (2.1–)2.5–3.7(–4.2) (n = 35) and lack a germ slit. Based on these traits L. gallicum is apparently a synonym of Eutypella grandis (Nitschke) Sacc.

Lopadostoma hawaiianum J.D. Rogers & Y.M. Ju, Canad. J. Bot. 80: 479. 2002.

Described from wood of Casuarina, Hawaii. A member of Lopadostoma subg. Anthostomopsis, i.e. not a species of Lopadostoma s.str.

Lopadostoma helicoides Lar.N. Vassiljeva, Novosti Sist. Nizsh. Rast. 27: 58. 1990.

On dead twigs of Kalopanax septemlobus in Primorye, Russia. Based on the protologue, this species does not belong to Lopadostoma because of the large ascospores (43–50 × 14–17 μm) having a spiralling germ slit.

Lopadostoma helveticum (Fuckel) P.M.D. Martin, J. S. African Bot. 42, 1: 75. 1976.

Basionym. Phaeosperma helvetica Fuckel, Jahrb. Nassauischen Vereins Naturk. 23–24: 224. 1870 (1869–1870).

Current name — Camarops microspora (P. Karst.) Shear (Boliniaceae), fide Nannfeldt (1972).

Lopadostoma massarae (De Not.) Traverso, Fl. Ital. Crypt. 1, 1, 1: 172. 1906.

Basionym. Hypoxylon massarae De Not., Sfer. Ital.: 17. 1863.

In corticated branches in Northern Italy, with a black stromatic line and dark disc; ascospores 20 × 8 μm. According to A. Graniti (pers. comm.) the species is indicated on the handwritten label of the sole specimen present in RO, as “Sphaeria Massarae DNtrs a Valtellina. Dr. Balsamo a Massara lecta 1836”. Unfortunately no response was obtained from RO, the name Lopadostoma massarae is therefore not interpretable. The only specimen present in PAD bearing this name consists of some pieces of bark of Carpinus betulus, with a polypore given as Poria contigua on the label and old, mostly disintegrated stromata of Melogramma campylosporum. No fungus matching the protologue could be found.

Lopadostoma microecium (Ellis & Everh.) P.M.D. Martin, J. S. African Bot. 42, 1: 75. 1976.

Basionym. Anthostoma microecium Ellis & Everh., Proc. Acad. Nat. Sci. Philadelphia 46: 344. 1894.

This is Coniochaeta cf. ligniaria fide Rappaz (1995), based on the type.

Lopadostoma microsporum (P. Karst.) P.M.D. Martin, J. S. African Bot. 35: 400. 1969.

Basionym. Anthostoma microsporum P. Karst., Fungi Fenniae Exsicc., Fasc. 9: no. 860. 1869.

= Phaeosperma microspora (P. Karst.) P. Karst., Not. Sallsk. Fauna Fl. Fenn. Forh. 13: 240. 1873.

Current name — Camarops microspora (P. Karst.) Shear (Boliniaceae), fide Nannfeldt (1972).

Lopadostoma ostropoides (Rehm) P.M.D. Martin, J. S. African Bot. 42, 1: 75. 1976.

Probably a Helicogermslita sp. fide Læssøe & Spooner (1994).

Lopadostoma polynesium (Berk. & M.A. Curtis) Rappaz, Mycol. Helv. 7, 1: 125. 1995.

Basionym. Sphaeria polynesia Berk. & M.A. Curtis, Grevillea 4, no. 32: 146. 1876.

A European specimen, which is morphologically in agreement with the description of L. polynesium by Rappaz (1995), was kindly provided by Alain Gardiennet: France, 21, Côte-d’Or, Savigny-le Sec, Combe Bonenfant, on Amelanchier ovalis, 5 May 2012, A. Gardiennet AG 12056 (WU 32088, culture LAG). This fungus superficially resembles the genus Eutypa, as perithecia are evenly immersed in a monostichous layer in light wood under a widely effused clypeus (blackened wood surface) and have long, non-clustered, vertically emerging, black ostioles. However, the ascospores are dark brown and narrowly ellipsoid to fusiform, not allantoid; they measure (8.5–)8.8–10.8(–12.0) × (3.5–)3.8–4.5(–4.8) μm, l/w = (1.8–)2.1–2.8(–3.4) (n = 30) and have an inconspicuous, narrow, straight, probably circumferential germ slit. They germinated very slowly (CMD) and only at low temperatures and the white, compact, c. 2 mm thick colonies with a peculiar brown (containing rosy and orange tones) reverse grew only at 15–20 °C on PDA, reaching a radius of c. 9 mm after 4.5 mo at 15 °C. LSU places this fungus outside Lopadostoma (Fig. 1). Yu-Ming Ju (pers. comm.) examined the holotype of L. polynesium and found that its ascospores contain a short germ slit, thus it is possible that the material from France is not the same species.

Lopadostoma pouzarii Granmo & L.E. Petrini, Mycol. Helv. 8, 1: 44. 1996.

Stromata of this species differ from those of Lopadostoma in being effused, erumpent from decorticated wood (of Fraxinus, Ulmus and Acer), containing non-clustered perithecia with broadly ellipsoid ascospores and are therefore in accordance with L. subg. Anthostomopsis, as determined by the authors. Two cultures of this fungus, kindly provided by Marc Stadler, were sequenced and found not to belong to Lopadostoma (Fig. 1), but they also do not cluster with L. cf. polynesium. According to Yu-Ming Ju (pers. comm.), L. pouzarii belongs to another xylariaceous genus, probably Whalleya J.D. Rogers, Y.M. Ju & San Martín.

Lopadostoma rhenanum (Fuckel) P.M.D. Martin, J. S. African Bot. 42, 1: 75. 1976.

Basionym. Fuckelia rhenana Fuckel, Jahrb. Nassauischen Vereins Naturk. 23–24: 224. 1870 (1869–1870).

Not a species of Lopadostoma. Described from Germany on Acer pseudoplatanus. Læssøe & Spooner (1994) studied two isotypes from K, which have (26–)32–37(–41) × 11.5–15(–17) μm large ascospores devoid of a germ locus.

Lopadostoma saprophilum (Ellis & Everh.) Rappaz, Mycol. Helv. 7, 1: 129. 1995.

Basionym. Anthostoma saprophilum Ellis & Everh., J. Mycol. 3, 4: 43 (1887).

USA, N.J., Newfield, in wood of Acer sp. Included by Rappaz (1995) in his L. subg. Anthostomopsis, hardly distinguishable from L. polynesium. Not a member of Lopadostoma.

Lopadostoma sphinctrinum (Kunze) P.M.D. Martin, J. S. African Bot. 42, 1: 75. 1976.

Basionym. Sphaeria sphinctrina Kunze, in Kunze & Schmidt, Mykologische Hefte (Leipzig) 2: 48. 1823.

Described as having circinate perithecia on Fagus sylvatica. This may be a synonym of L. turgidum, but no type material is extant in B and TUB, therefore the name remains dubious.

Lopadostoma stictoides (Ellis & Everh.) P.M.D. Martin, J. S. African Bot. 42, 1: 83. 1976.

Basionym. Anthostoma stictoides Ellis & Everh., nom. nud.

According to Martin (1976) stromata are immersed in wood of Crataegus, have white ostioles and brown ascospores 17.5 × 11 μm. This is based on the type, which was collected by Dearness in London, Ontario in 1892 and incorporated in the herbarium of Ellis in 1899 (NY). Læssøe & Spooner (1994) interpreted this fungus as a Helicogermslita sp.; see also Barr et al. (1996).

Lopadostoma taeniosporum (Sacc.) Traverso, Fl. Ital. Crypt., Pars 1: Fungi. Pyrenomycetae, Xylariaceae, Valsaceae, Ceratostomataceae 1, 1: 171. 1906.

Basionym. Anthostoma taeniosporum Sacc., Atti Soc. Veneto-Trentino Sci. Nat. Padova 2: 143. 1873.

Described from Italy in bark of Quercus pedunculata (a synonym of Quercus robur). The holotype (PAD) was briefly examined. Perithecia of this fungus are not obviously stromatic, but clustered in bark fissures. Asci are cylindrical, inamyloid and contain 8 uniseriate ascospores. Ascospores are broadly ellipsoid, (17.0–)17.5–20.5(–24.5) × (9.8–)10.7–12.7(–14.5) μm, l/w = 1.4–1.8(–2.5) (n = 35), unicellular, slightly laterally compressed, dark brown, equilateral, without sheath or appendages, and contain a unilateral, straight, spore-length germ slit. According to the protologue, stromata are first immersed in bark, become free and become disintegrated to liberate perithecia. The generic affiliation of L. taeniosporum is unclear, but the fungus clearly does not belong to Lopadostoma.

Lopadostoma turgidum var. minus Sacc., Ann. Mycol. 6: 558. 1908.

Described from France, near Paris, on Quercus or Castanea with ascospores 8–9 × 4.5–5 μm. Doubtful, no material preserved in PAD.

Lopadostoma turgisporum Lar. N. Vassiljeva, Pirenomits. Lokuloaskomits. Severa Dal’nego Vostoka (Leningrad): 200. 1987.

Described from Betula ermanii in Siberia, with ascospores 8–10 × 6–7 μm. This species may belong to Lopadostoma. It was not examined.

DISCUSSION

Most genera of the Xylariaceae form true stromata, which are by definition entirely composed of fungal tissue. Others, such as Anthostomella, Euepixylon, Helicogermslita, Leptomassaria or Lopadostoma form pseudostromata, which contain a mixture of fungal and host tissue. We studied one of the latter genera, Lopadostoma, which contained only few species, until Martin (1969, 1976) combined names of many unrelated fungi into this genus, and before Rappaz (1995) added his subgenus Anthostomopsis.

Delimitation of genera in the Xylariales and Xylariaceae has been based on morphology, asexual morphs and more recently also secondary metabolites (Læssøe & Spooner 1994, Ju & Rogers 1996, 1999, Bitzer et al. 2008), while DNA data have played a secondary role. A considerable number of nuclear DNA sequences of the ribosomal cluster are available in GenBank, but because of low variation in combination with homoplasy and thus low power of resolution (LSU), or poor alignability due to high length variability (ITS), sound phylogenetic and evolutionary inferences using markers like LSU and/or ITS are limited.

However, a phylogenetic analysis based on LSU (Fig. 1) was sufficient to make clear that Lopadostoma, which we reduce here to species with pustular stroma development in bark of broad-leaved trees and shrubs, forms a monophylum within the Xylariaceae, while Lopadostoma subg. Anthostomopsis, represented by the two species L. cf. polynesium and L. pouzarii do not belong to the genus. It is currently, however, not possible to establish a generic name for L. subg. Anthostomopsis, because the two species included do not fall into the same clade, i.e. this ‘subgenus’ is phylogenetically heterogeneous. More freshly collected material is needed to draw a clear picture of this assemblage of species. It appears also that the few accessions labelled with the generic name Anthostomella do not cluster together, i.e. this genus seems to be highly polyphyletic.

Sequences of protein-coding genes such as act, tub and rpb2 have been shown to be superior to the ribosomal cluster in genera closely related to Hypoxylon (Hsieh et al. 2005) and in Xylaria (Hsieh et al. 2010), but they are only available for few taxa of Xylariaceae. We used rpb2 in combination with ITS and LSU to study species delimitation in Lopadostoma in detail (Fig. 2). Clustering of intraspecific isolates using this marker correlated well with morphology and hosts, except for L. meridionale, which is split into several well-supported subclades, despite uniformity of specimens and hosts. In L. meridionale, high genetic variability of these markers is present even within a small geographic area (see phylogenetic positions of LG29, LG33, LG34 and LG35, all sampled in northern Corfu, Greece, or LG and LG36 sampled in south-western Istrija, Croatia). The significance of this result is not clear, we therefore leave the subclades of the L. meridionale clade taxonomically unresolved for the time being. In addition, morphological similarities among species are not reflected by the rpb2/ITS/LSU tree topology; for instance, L. linospermum and L. dryophilum, which share distinctly yellow-brown to olivaceous entostroma between ostiolar necks and large asci and ascospores are not closely related (Fig. 2).

Many species of Lopadostoma are morphologically difficult to distinguish, because of overlap of many features and considerable intraspecific variation, in part caused by changes of climatic factors during stroma development and maturation. Furthermore, sizes of L. gastrinum-like stromata (most species) are correlated with the diameter of the twig or branch on which they occur, i.e. with bark thickness and accordingly substrate availability. Thus qualitative characters like the colour of stromatic tissue between ostiolar necks or presence or absence of a black stromatic line around individual perithecial clusters, are more informative than quantitative ones (diameter of stromata, number of perithecia and their size), i.e. most morphological characters are too variable to be discriminant. More important is the combination of ascospore size, stroma colour between ostioles and hosts. Lopadostoma encompasses mostly host-specific species, but L. gastrinum is plurivorous, with marked abundance on Ulmus spp. To a lesser extent, also other species may occur on different, but closely related hosts. As an exception, L. fagi was once found on Corylus, which is not closely related to its typical host. Slight differences of this strain from Fagus-isolates might eventually indicate a good species on a very fine-tuned scale. Species on Quercus may occur on different host species, which usually fall into different subgenera of Quercus. The diversity of Lopadostoma on the latter genus is by far the highest. Thus it is expected that regions with a high diversity of Quercus spp., such as North America and Mexico, may be home to additional undescribed species of Lopadostoma. So far, we have only seen one report of a Lopadostoma sp. (as L. turgidum) by San Martín & Lavin (1997) from Quercus sp. in Mexico with small ascospores (8–9.5(–11) × 3.5–4 μm).

Such concentration of bark-inhabiting species on a certain host genus is conspicuous, as other genera of similar ecology, e.g. Massaria and Prosthecium (Stegonsporium) on Acer (Voglmayr & Jaklitsch 2008, 2011) and Melanconiella on Carpinus and the closely related genus Ostrya (Voglmayr et al. 2012) behave similarly.

Based on current collections, the spatial distribution of Lopadostoma as circumscribed here appears to be restricted to temperate and Mediterranean Europe and to a lesser extent to North America. Remarkably, no confirmed records are known to us from East Asia, despite the widespread presence of suitable host genera like Ulmus, Fagus and Quercus, which may indicate that this region is largely understudied.

Species of Lopadostoma are generally not particularly common, but show a marked seasonal occurrence. Like many other pyrenomycetes they occur throughout Europe mostly in spring (March to May with a peak in April) and in autumn (September to November). During these periods they may be abundant in regions, where the respective hosts are common. Some species, particularly those on Fagus, viz. L. fagi and L. turgidum, may be also common in summer, depending on moisture.

Acknowledgments

REFERENCES