Phytotaxa 536 (1): 083–091 https://www.mapress.com/pt/ Copyright © 2022 Magnolia Press ISSN 1179-3155 (print edition) Article PHYTOTAXA ISSN 1179-3163 (online edition) https://doi.org/10.11646/phytotaxa.536.1.5 Four new species of Herpothallon (Arthoniaceae, Arthoniales, Arthoniomycetes, Ascomycota) from China PENGFEI CHEN1,3, LINLIN LIU1,4, CONGMIAO XIE2,5 & LULU ZHANG1,6* 1 Institute of Environment and Ecology, Shandong Normal University, Jinan, 250014, P. R. China. Key Laboratory of Plant Stress Research, College of Life Sciences Shandong Normal University, Jinan, 250014, P. R. China. 3
649446910@qq.com; https://orcid.org/0000-0002-6699-869X 4
2743868377@qq.com; https://orcid.org/0000-0003-3571-7119 5
xiecongmiao@outlook.com; https://orcid.org/0000-0001-9973-3594 6
612038@sdnu.edu.cn; https://orcid.org/0000-0001-8011-4451 *Corresponding author:
612038@sdnu.edu.cn 2 Abstract Four new species of Herpothallon: H. capilliferum, H. polyisidiatum, H. subglobosum and H. viridi-isidiatum are described from southern China. Detailed taxonomic descriptions, ecological and chemical characters, and illustrations are provided for the new species. A key to all known Chinese Herpothallon species is also provided. Keywords: Cryptothecia, East Asia, lichenized fungi, taxonomy Introduction The genus Herpothallon (Arthoniaceae, Arthoniales, Arthoniomycetes, Ascomycota) is typically known from tropical and subtropical regions. It was first described by Tobler in 1937 and was reinstated by Aptroot et al. (2009). The genus is recognized by a corticolous, rarely saxicolous foliicolous or lignicolous, crustose thallus, loosely to firmly attached to the substratum, usually forming rounded to irregular patches 3–10 cm diam. that are almost white, pale yellowish, greenish-grey, green or with a yellow, orange or red colouration and the medulla reacts I–. Except for a few species, almost all have calcium oxalate crystals in the thallus. Pseudisidia or pseudisidioid structures are often present, and concolorous with the thallus or rarely paler (Aptroot et al. 2009). The genus is similar to Cryptothecia (Arthoniaceae, Arthoniales, Arthoniomycetes, Ascomycota) in its ecology, distribution and byssoid thallus, but pseudisidia and pseudisidia-like structures are unknown in Cryptothecia s. str., and the thallus of Cryptothecia species is usually more tightly attached to the substrate lacking a byssoid hypothallus, and the medulla reacts I+ blue in patches (Aptroot et al. 2009). The genus Herpothallon comprises approximately 44 species worldwide (Aptroot et al. 2009; Jagadeesh et al 2009; Frisch et al. 2010; Jagadeesh & Sinha 2011; Cheng et al. 2012; Bungartz et al. 2013; Frisch et al. 2014; Jagadeesh & Sinha 2014; Seavey & Seavey 2014; Aptroot et al. 2017; Sipman 2018), and until recently only four species had been reported from China (Aptroot et al. 2009; Cheng et al. 2012). During our study on the crustose lichens in southern China, four species of Herpothallon new to science were found. Material & methods The specimens studied were collected in Yunnan, Guangdong and Zhejiang Provinces, China, and are preserved in the Lichen Section of the Botanical Herbarium, Shandong Normal University, Jinan, China (SDNU) and Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China (KUN). The morphological and anatomical characters were examined under a stereomicroscope (COIC XTL7045B2) and a polarizing microscope (Olympus CX41). The thallus and medulla were tested with K (a 10% aqueous solution of potassium hydroxide), C (a saturated solution of Accepted by Christian Printzen: 2 Feb. 2022; published: 22 Feb. 2022 83 aqueous sodium hypochlorite), P (a saturated solution of p-phenylenediamine in 95% ethyl alcohol), and I (Lugol’s iodine) for identification. Polarized light (pol) was used to locate crystals in the sections. The lichen substances were identified using standardized thin-layer chromatography techniques (TLC) with systems A, B’ and C (Orange & al. 2001). Photos were taken under Olympus SZX16 and BX61 with DP72. Results Herpothallon capilliferum P.F. Chen & L.L. Zhang, sp. nov. (Figure 1) Mycobank number: 839108 Type:—CHINA. Zhejiang: Lishui City, Jingning County, Dayang Lake Nature Reserve. 1405.34 m elev., 27°52′11.43″ N, 119°43′51′′ E, on bark of Nyssa sinensis Oliv., 3 December 2020, C.G. Zhao & L.L. Zhang 20200807 (Holotype in SDNU). Description:—Thallus corticolous, up to 4 cm in diam., loosely appressed to the substrate, sometimes flaking off, minutely felty, dull, pale mineral grey to olivaceous green; in section up to 100 μm thick, with abundant calcium oxalate crystals throughout the thallus. Hypothallus whitish, byssoid, composed of 1–2 μm wide hyphae. Prothallus up to 1 mm broad, byssoid, composed of interwoven and radiating hyphae, whitish. Pseudisidia numerous, irregular, globose, unbranched, byssoid, with abundantly projecting hyphae, mostly white but sometimes green in parts, up to 0.4 × 0.2 mm. Photobiont Trentepohlia, single to aggregated, cells globose, 7–10 × 5–7 μm, yellowish green. Asci and pycnidia not seen. Chemistry and spot tests:—Thallus and prothallus K+ yellow and then red, C–, P+ yellow, I–. TLC: norstictic acid. Etymology:—The epithet “capilliferum” refers to the hair-like appearance of pseudisidia. Ecology and distribution:—The new species was found growing on Nyssa sinensis Oliv., in Dayang Lake Nature Reserve of Zhejiang Province. Specimen examined:—CHINA. Zhejiang: Lishui City, Jingning County, Dayang Lake Nature Reserve. 1405.34 m elev., on bark of Nyssa sinensis Oliv., 3 December 2020, C.G. Zhao & L.L. Zhang 20200808, 20200809 (SDNU). Note:—This species is characterized by pseudisidia with many projecting hyphae and the presence of norstictic acid as a major secondary metabolite. Herpothallon coralloides Jagadeesh (2014: 40) is also pseudoisidiate and contains norstictic acid, but it has a pale green to whitish grey thallus that also contains confluentic acid and much larger pseudisidia (up to 1.0 × 0.1mm) that are felty, but without projecting hyphae (Jagadeesh 2014). The morphologically most similar species is Crypthonia albida (Fée) Frisch & G. Thor (2010: 290) but C. albida contains psoromic acid and pseudisidia that are larger (up to 1.0 × 0.5 mm). Another morphologically similar species is H. minimum Aptroot & Lücking (2009: 53), it is the only known Herpothallon species that produces 2’-O-methylperlatolic acid (Aptroot et al. 2009). Herpothallon polyisidiatum P.F. Chen & L.L. Zhang, sp. nov. (Figure 2) Mycobank number: 839109 Type:—CHINA. Guangdong: Qingyuan City, Mangshan Forest Park. 1716 m elev., 24°55′22.85″ N, 112°59′35.67″ E, on bark of trees, 17 May 2019, L.S. Wang & X.Y. Wang 66649 (Holotype in KUN) Description:—Thallus corticolous, up to 4 cm in diam., closely appressed to the substrate, firm and sometimes flaking off, minutely felty, dull, yellowish white to light yellow, in section up to 150 μm thick, with many calcium oxalate crystals in the thallus. Hypothallus byssoid, white, composed of 1–3 μm wide hyphae. Prothallus up to 1 mm broad, byssoid, composed of interwoven and radiating hyphae, whitish. Pseudisidia numerous, cylindrical, unbranched or sparsely branched, rather compact yet felty, of the same colour as thallus, up to 0.3 × 0.1 mm. Photobiont Trentepohlia, single or a few cells aggregated, cells globose, 6–10 × 5–8 μm, yellowish green. Asci and pycnidia not seen. Chemistry and spot tests:—Thallus K+ yellow, C–, P+ orange, I–. TLC: stictic acid. Etymology:—The epithet “polyisidiatum” refers to abundant pseudisidia. Ecology and distribution:—The new species was found growing on bark of a tree in Mangshan Forest Park. 84 • Phytotaxa 536 (1) © 2022 Magnolia Press CHEN ET AL. FIGURE 1. The new species Herpothallon capilliferum (holotype, SDNU 20200807). FOUR NEW SPECIES OF HERPOTHALLON Phytotaxa 536 (1) © 2022 Magnolia Press • 85 FIGURE 2. The new species Herpothallon polyisidiatum (holotype, KUN 66649). 86 • Phytotaxa 536 (1) © 2022 Magnolia Press CHEN ET AL. FIGURE 3. The new species Herpothallon subglobosum (holotype, KUN 82-76). FOUR NEW SPECIES OF HERPOTHALLON Phytotaxa 536 (1) © 2022 Magnolia Press • 87 FIGURE 4. The new species Herpothallon viridi-isidiatum (holotype, SDNU 20200806). Note:—This species can be distinguished by its compact pseudisidia and the presence of stictic acid as the only metabolite. Herpothallon sticticum Jagadeesh Ram & Sinha (2011: 314), H. isidiatum Jagadeesh Ram & Sinha (2009: 611) and H. elegans G. Thor (2009: 39) also contain stictic acid, but H. sticticum has a grey to pale yellow–grey thallus and dense, minutely felty, granular globular to short cylindrical 0.05–0.1(–0.25) × 0.05–0.1(–0.2) mm wide pseudisidia with projecting hyphae (Jagadeesh & Sinha 2011); H. isidiatum has a grey to whitish grey thallus and 88 • Phytotaxa 536 (1) © 2022 Magnolia Press CHEN ET AL. larger pseudisidia (0.08–0.15 × 0.5–1.5 mm) with dark brown to black pycnidia at the tips (Jagadeesh & Sinha 2009); H. elegans has a hypothallus with a red layer (partly absent) and with a smooth and black layer and dark red prothallus beneath that (Aptroot et al. 2009). This species can also be confused with Diorygma antillarum (Vain.) Nelsen, Lücking & Rivas Plata (2012: 318). In Diorygma, the hypothallus is compact, not byssoid, and pseudisidia are unknown with the exception of D. antillarum, which has a distinct carbonized hypothallus, but contains different substances from H. polyisidiatum (Nelsen et al. 2012). Herpothallon subglobosum P.F. Chen & L.L. Zhang, sp. nov. (Figure 3) Mycobank number: 839110 Type:—CHINA. Yunnan: Diqing Tibetan Autonomous Prefecture, Weixi County, Baimaluo. 2100 m elev., 27°45’30.96” N, 99°2’26.53” E, on bark of trees, 7 May 1982, L.S. Wang 82–76 (Holotype in KUN) Description:—Thallus corticolous, up to 5 cm in diam., tightly attached to the substrate, firm, or sometimes flaking off, minutely felty, dull, white to grey, with many calcium oxalate crystals. Hypothallus byssoid, white, composed of 1–2 μm wide hyphae. Prothallus up to 1 mm wide, white, byssoid, composed of interwoven and radiating hyphae. Pseudisidia numerous, of the same colour as the thallus, globular, up to 0.1 × 0.1 mm. Photobiont Trentepohlia, single or a few cells aggregated, cells globose, 5–10 × 4–8 μm, yellowish green. Asci and pycnidia not seen. Chemistry:—Thallus K–, C+ bright red, P–, I– medulla. TLC: gyrophoric acid, lecanoric acid, umbilicaric acid. Etymology:—The epithet “subglobosum” refers to globular pseudisidia. Ecology and distribution:—Herpothallon subglobosum was found growing on bark of trees in a subtropical forest of Yunnan Province. Note—This species is characterized by a tightly attached thallus, small globular pseudisidia and the presence of gyrophoric acid, lecanoric acid, umbilicaric acid. Other Herpothallon species with pseudisidia and gyrophoric acid include H. fertile Aptroot & Lücking (2009: 40), H. himalayanum Jagadeesh Ram & Sinha (2009: 40), H. japonicum (Zahlbr.) G. Thor (2009: 44), H. minutum Jagadeesh Ram (2014: 45), and H. philippinum (Vain.) Aptroot & Lücking (2009: 56). Herpothallon fertile is a Herpothallon species with asci and ascospores. Other characteristics also distinguish the new species from the non-fertile ones: H. himalayanum has a loosely appressed thallus, with a hypothallus that is mostly lemon yellow and the species has larger pseudisidia (up to 1 × 0.5 mm); H. japonicum has a more distinctly C+ red thallus (gyrophoric acid, ovoic acid, lecanoric acid and 2-O-methyllecanoric acid), cylindrical pseudisidia (up to 0.7 × 0.2 mm) and its thalli lack calcium oxalate (Aptroot et al. 2009); H. minutum has a greenish grey to greyish yellow thallus and dense, minute, granular globular to short cylindrical 0.02–0.06 mm wide pseudisidia (Jagadeesh Ram 2014); H. philippinum has frequent and large, slender pseudisidia. Herpothallon viridi-isidiatum P.F. Chen & L.L. Zhang, sp. nov. (Figure 4) Mycobank number: 839111 Type:—CHINA. Zhejiang: Lishui City, Jingning County, Baiyun Protection Station. 1298.73 m elev., 27°43′11.07″ N, 119°38′49.33″ E, on bark of Cunninghamia lanceolata (Lamb.) Hook., 2 December 2020, C.G. Zhao & L.L. Zhang 20200806 (Holotype in SDNU) Description:—Thallus corticolous, up to 3–5 cm in diam., loosely appressed to the substrate, sometimes flaking off, minutely felty, dull, pale mineral greyish-green, in section up to 150 μm thick, with many calcium oxalate crystals in the thallus. Hypothallus byssoid, dirty whitish, composed of 1–3 μm wide hyphae. Prothallus up to 1 mm wide, byssoid, composed of interwoven and radiating hyphae, dirty white in inner and whitish to pale brown in outer parts. Pseudisidia numerous, cylindrical, branched, rather compact yet felty, of the same colour as thallus or often paler in the upper part, up to 0.2 × 0.1 mm. Photobiont Trentepohlia, single or a few cells aggregated, cells globose, 7–12 × 4–8 μm, yellowish green. Asci and pycnidia not seen. Chemistry and spot tests:—Thallus and prothallus K+ yellow, C+ red, P+ pale yellow, I+ blue in medulla. TLC: gyrophoric acid, lecanoric acid, umbilicaric acid and unknown substances. Etymology:—The epithet “viridi-isidiatum” refers to the green colour of the pseudisidia. Ecology and distribution:—The new species was found growing on Cunninghamia lanceolata (Lamb.) Hook., at Baiyun Protection Station. Specimen examined:—CHINA. Zhejiang: Lishui City, Jingning County, Baiyun Protection Station. 1298.73 m FOUR NEW SPECIES OF HERPOTHALLON Phytotaxa 536 (1) © 2022 Magnolia Press • 89 elev., on bark of Cunninghamia lanceolata (Lamb.) Hook., 2 December 2020, C.G. Zhao & L.L. Zhang 20200810 (SDNU). Note:—This species is characterized by cylindrical pseudisidia with many hyphae on the surface and the presence of gyrophoric acid, lecanoric acid, umbilicaric acid. Although H. philippinum also has a C+ red thallus and prothallus (gyrophoric acid, ± confluentic and/or lecanoric acids), it has felty pseudisidia with projecting hairs (up to 1.0 × 0.1 mm). Herpothallon echinatum Aptroot, Lücking & Will-Wolf (2009: 38) also has a loosely appressed thallus, but contains psoromic acid and lacks calcium oxalate (Aptroot et al. 2009). Another morphologically similar species is H. isidiatum, but the species is characterized by stictic acid and smaller pseudisidia with dark brown to black pycnidia at the tips (Jagadeesh & Sinha 2009). Conclusion Here we present a brief diagnosis of Herpothallon, a key to all species currently known from China with detailed descriptions of the four newly described species as the scientific basis for further study of the genus in China. Our study documents a high diversity in species from the Zhejiang and Yunnan Provinces in the context of the Lichen Flora of China project. In the future, we are planning a survey on lichen diversity in Fujian Province. We anticipate that further studies are necessary to fully understand the circumscription of the genus in China. We hope that this work encourages other researchers to pay more attention to these intriguing lichens as an important element of cryptogamic communities in tropical and subtropical regions. Acknowledgements We thank Prof. André Aptroot (ABL Herbarium, The Netherlands) for presubmission review. We are grateful to Dr. Li-song Wang and Dr. Xin-yu Wang (Kunming Institute of Botany, China) for sending specimens. This work was supported by the Emergency Management Project of the National Natural Science Foundation of China (31750001). Key to the species of Herpothallon known from China 1 2 3 4 5 6 7 8 - Pigments in thallus visible from above, prothallus with red pigment, K+ purple; pseudisidia cylindrical or globose ........................ .................................................................................................H. rubrocinctum (Ehrenb.) Aptroot, Lücking & G. Thor (2009: 61) No pigments in thallus, pseudisidia and prothallus visible from above (rarely yellow pigments located in hidden hypothallus) ...... ............................................................................................................................................................................................................2 Thallus with globose to granular pseudisidia .....................................................................................................................................3 Thallus with cylindrical pseudisidia ...................................................................................................................................................6 Thallus K– and perlatolic acid present ..........................................................H. granulare (Sipman) Aptroot & Lücking (2009: 43) Thallus K–/K+ yellow to red and perlatolic acid absent ....................................................................................................................4 Psoromic acid chemosyndrome .................................................................................. H. weii Y.L. Cheng & H.Y. Wang (2012: 440) Different substances ...........................................................................................................................................................................5 Gyrophoric present (C+ bright red, K–) ....................................................................................................................H. subglobosum Norstictic acid present (C– and K+ orange) ............................................................................................................... H. capilliferum Gyrophoric present (C+ bright red) ....................................................................................................................................................7 Gyrophoric absent (C–) ......................................................................................................................................................................8 Thallus K+ yellow, pseudisidia smaller (up to 0.2 × 0.1 mm) .............................................................................. H. viridi-isidiatum Thallus K–, pseudisidia larger (up to 1.0 × 0.1 mm) .................................................................................................. H. philippinum Psoromic acid (P+ golden yellow) present .................................................................................................................... H. echinatum Stictic acid present (P+ orange)................................................................................................................................ H. polyisidiatum References Aptroot, A., Thor, G., Lücking, R., Elix, J.A. & Chaves, J.L. (2009) The lichen genus Herpothallon reinstated. Bibliotheca Lichenologica 99: 19–66. [http://www.nhm2.uio.no/botanisk/lav/RLL/PDF/R30504.pdf] Aptroot, A., Gumboski, E.L., Cáceres, M.E.S. (2017) New Arthoniales from Santa Catarina (South Brazil). Cryptogamie, Mycologie 38 (2): 275–281. 90 • Phytotaxa 536 (1) © 2022 Magnolia Press CHEN ET AL. https://doi.org/10.7872/crym/v38.iss2.2017.275 Cheng, Y.L., Ning, J., Xu, H.P., Zhang, L.L., Wang, H.Y. & Zhao, Z.T. (2012) Herpothallon weii, a new lichen from China. Mycotaxon 119: 439–443. http://dx.doi.org/10.5248/119.439 Frisch, A., Elix, J.A. & Thor, G. (2010a) Herpothallon biacidum, a new lichen species from tropical Australia. 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