Herpothallon subglobosum P.F. Chen & L.L. Zhang, 2022

Chen, Pengfei, Liu, Linlin, Xie, Congmiao & Zhang, Lulu, 2022, Four new species of Herpothallon (Arthoniaceae, Arthoniales, Arthoniomycetes, Ascomycota) from China, Phytotaxa 536 (1), pp. 83-91 : 89

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.

Figures

FIGURE 3. The new species Herpothallon subglobosum (holotype, KUN 82-76).