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Festuca of North America

S.G. Aiken, M.J. Dallwitz, C.L. McJannet, and L.L. Consaul

Festuca earlei Rydb.

Bull. Torrey Bot. Club 32: 608. 1905. Type: U.S.A. Colorado: La Plata Canyon, 9500 ft., 11 July 1898, C.F. Baker, F.S. Earle, S.M. Tracy 920. Holotype: NY!

Festuca brevifolia var. utahensis St.-Yves, Candollea 2: 254. 1925. F. brachyphylla var. utahensis (St.-Yves) Litard., Candollea 10: 108. 1945. Type: U.S.A. Colorado: near Pagosa Peak, August 1899, C. F. Baker 176. Lectotype: GH! (Frederiksen 1979).

This taxon has been treated as a synonym of F. rubra (Hitchcock and Chase 1951), and as a synonym of F. minutiflora (Frederiksen 1979).

Habit. Plants yellowish green, 15–45 cm high, not densely tufted (tufts looser than those of F. minutiflora), tiller bases not stiffly erect, bases purplish or not purplish (usually), horizontal rooting stems absent. Vegetative shoots arising outside, or breaking through the base of existing sheaths.

Vegetative morphology. Sheaths glabrous, not conspicuous at the base of the plant, splitting between the veins (fibrillose and reddish brown, similar to F. rubra but without retrorse trichomes), open more than half their length (approximately, but splitting early; among the sheaths occur fragile prophylls 1.5–2.5 cm long with trichomes on the veins and elsewhere scaberulous). Collars glabrous. Auricles represented by distinct, erect, swellings (that are more or less prominent). Auricular cilia absent. Ligules 0.1–1 mm long (higher on the sides at the auricles), ciliate. Leaf blades 6–12 cm long, erect, stiffish or more or less lax. Adaxial blade surfaces with trichomes (sparse), abaxial blade surfaces glabrous. Leaf blades flat or plicate (flag leaves often flat), 1–3 mm wide; 0.2–0.43–0.6 mm wide, 0.5–0.7–0.85 mm deep. Veins 5. Adaxial to abaxial sclerenchyma strands absent. Abaxial sclerenchyma poorly developed, in discrete, relatively narrow strands opposite the veins. Ribs 1 (well defined, 2–4 usually well defined). Uppermost culm leaf sheaths not inflated. Flag leaf blades 2–8 cm long. Culm nodes becoming exposed, 1; internodes glabrous.

Floral morphology. Inflorescence 3–6.5(–8) cm long. Inflorescence branches at the lowest node 2, appressed after anthesis, 0.5–2 cm long. Rachis angular in cross section, trichomes mainly on the ridges. Spikelets loosely scattered in an open panicle with slender branches (solitary, or with 2–3 spikelets on the short branches); 1–4 on the longest branches; 4.3–6.2 mm long, 1.8–3(–4) mm wide. Proliferating spikelets absent. Florets 2–4. Glumes unequal (sometimes approaching subequal), with trichomes, vestiture at the apex only (slightly scabrous), margins ciliate. First glume 2.2–3 mm long, veins 1(–3). Second glume shorter than the first lemma, 2.7–3.7 mm long, veins 3. Rachilla internodes 0.9–1.1 mm long, antrorsely scabrous (trichomes delicate). Lemma callus not elongated. Lemma 3.2–4.5 mm long, nerveless in dorsal view or sometimes with only the centre vein distinct, with trichomes (scabrous), trichomes on the upper portion only; apex entire. Lemma awn 0.4–1.6 mm long. Palea 3.7–4.2 mm long, distinctly pubescent between the keels (sometimes sparsely so). Lodicules with marginal teeth or without marginal teeth, glabrous, 0.4–1 mm long. Anthers (0.6–)0.8–1.4 mm long. Ovary apex pubescent (hairs dense). Caryopsis 2.5–3 mm long.

Habitat and distribution. Native; alpine (reported from 2,800–4000 m, growing on talus slopes, dry grasslands in meadows of spruce and Pinus contorta woods). Above 2800 m; Southwestern USA: Ariz.; Rocky Mountains USA: Colo., Utah; South Central USA: N. Mex.

Classification. Subg. Festuca L.

Notes. Festuca earlei has a densely hairy ovary, a character that is present in other ovina-like species, e.g. F. occidentalis Hook., and one that distinguishes F. earlei from F. rubra L., as do the anther lengths (less than 1 mm long in F. earlei. and more than 2 mm in F. rubra). When Rydberg (1905) described F. earlei as a new species, he claimed it was related to F. rubra.

Some specimens of F. earlei were described by St.-Yves (1925) as F. brevifolia var. endotera St.-Yves and F. brevifolia var. utahensis St.-Yves. The collection, Baker 175, was cited as an example of the latter taxon. Two sheets of the Baker 175 collection, borrowed from RM, have slightly smaller plants than many specimens of F. earlei (when compared with size ranges in this database). St.-Yves (1925) cited both Baker 175 and 176 as examples of F. brevifolia var. endotera. Frederiksen (1979) placed both subspecies in synonymy with F. minutiflora Rydb., but commented that she included F. brevifolia var. utahensis only with some hesitation, pointing out that it deviates from F. minutiflora especially in having more florets per spikelet and broader leaves. She claimed to have found transitional specimens even among the few specimens examined. Some specimens annotated by Frederiksen as F. minutiflora are plants of F. earlei. Cronquist et al. (1977) placed F. brevifolia var. endotera in synonymy with F. ovina, indicating that there were numerous collections cited from the western U.S. and Canada.

Alexeev (1982), as translated from Russian, stated that "this is the only North American species with small anthers (0.6–0.75 mm long), extravaginal shoot regeneration, short underground rhizomes, and sheaths that are closed almost to the top. We know of only two Central Asiatic species with this combination of characters - F. venusta St.-Yves and F. nitidula Stapf. St.-Yves (1925) assigned the type specimen of F. earlei to a variety that he described, i.e., F. brevifolia var. endotera, which represents a conglomerate of four small-anthered species: F. brachyphylla Schult. & Schult. f., F. minutifolia Rydb., F. saximontana Rydb., and F. earlei. Only two of these - F. earlei and F. minutiflora - have a pilose ovary, and only one - F. earlei - has extravaginal shoots."

In the course of the study, the first author has examined approximately 30 specimens of F. earlei without finding evidence of the horizontal "short underground rhizomes" referred to by Alexeev (1982). Some samples have evidence of an etiolated basal "tussock" and short vertical stems from which roots arise. Both F. earlei and F. minutiflora show phenotypic plasticity with evidence on herbarium labels suggesting that small and large plants have often come from different microhabitats, even at the same location (for example Baker 175 and 176). Large specimens of F. earlei are sufficiently robust to have been identified as F. rubra, while many specimens of F. minutiflora have previously been identified as F. brachyphylla. Large specimens of F. minutiflora approach the dimensions of small to medium size specimens of F. earlei, but have a finer more delicate form when the two species are compared.

The nearest neighbour of F. earlei in distance matrices, generated by the DELTA program DIST from this database, is F. brachyphylla subsp. brachyphylla. Twelve other taxa classified as F. ovina-like are nearer than the closest taxon of the F. rubra complex. The leaf anatomy in cross section was considered more ovina-like (Aiken and Consaul 1995).

Illustrations. • Isotype specimen, Baker 175: RM. Herbarium specimen of name in synonymy, cited as an example of F. brevifolia var. endotera St.-Yves, (1925, Candollea 2: 254). U.S.A. Colorado, Pagosa Peak, 12,000', Aug. 1899. Baker 175. Isotype: RM. • Isotype specimen, Baker 175: RM. A second herbarium specimen of F. earlei, cited as an example of F. brevifolia var. endotera St. -Yves (1925, Candollea 2: 254). U.S.A. Colorado, Pagosa Peak, 12,000', Aug. 1899. Baker 175. Isotype: RM. • Holotype specimen, NY. Photograph of holotype specimen of Festuca earlei annotated by L.E. Pavlick and E.B. Alexeev. U.S.A. Colorado, La Plate Canon, 12,000', 11 July 1898 Aug. 1899. C.F. Baker, F.S. Earle, and S.M. Tracy 920. Holotype: NY!. • Herbarium specimen: COLO. Herbarium specimen of F. earlei from Colorado. Photograph of the specimen is at DAO. Annotated as F. minutiflora by S. Frederiksen, March 1979, re-examined by S. Aiken (1994) and considered to be F. earlei. U.S.A. Colorado. Clear Creek Co.: tundra slopes, 12000 ft. alt., head of Stevens Gulch, north base of Gray's Peak. Aug. 5, 1950, W.A. Weber 5938. COLO 61549. • Herbarium specimen of interest. Herbarium specimen annotated as Festuca minutiflora Rydb. by Signe Frederiksen in 1982 after she had published the paper, "Festuca minutiflora a neglected species" in 1979. This specimen, considered by us to be F. earlei contrasts with the specimen lectotypified by S. Frederiksen as the type of F. minutiflora. (Illustrated with that species). • Leaf anatomy. Leaf cross section of F. earlei. Leaf blades are 0.2–0.43–0.6 mm wide and 0.5–0.7–0.85 mm deep, with 5 veins. Adaxial to abaxial sclerenchyma strands are absent. Abaxial sclerenchyma strands are poorly developed, in discrete, relatively narrow strands opposite the veins. There is one well defined rib and 2–4 usually well defined ribs. • Distribution map


We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations with detailed captions, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.


Cite this publication as: ‘Aiken, S.G., Dallwitz, M.J., McJannet, C.L. and Consaul, L.L. 1996 onwards. Festuca of North America: descriptions, illustrations, identification, and information retrieval. Version: 14th February 2019. delta-intkey.com’. Aiken, Dallwitz, McJannet, and Consaul (1997) should also be cited (see References).

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