Herpothallon viridi-isidiatum 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 : 89-90

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 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).

Figures

FIGURE 4. The new species Herpothallon viridi-isidiatum (holotype, SDNU 20200806).