Herpothallon, Tobler, 1937

Liu, Linlin, Zuo, Qijia, Xue, Junxia, Ren, Zhaojie & Zhang, Lulu, 2023, Three new species of Herpothallon (Lichenized Ascomycota) from Southern China, Phytotaxa 597 (4), pp. 287-296 : 294-295

Key to the species of Herpothallon known from China

1. Prothallus and pseudisidia with red pigment, K+ purple in pigmented parts.......................................................... H. rubrocinctum 1 Prothallus and pseudisidia without red pigment (rarely pinkish or lilac pigments present in pseudisidia) ....................................... 2

2. Thallus C+ red; gyrophoric acid major, lecanoric acid and some other substances minor ................................................................ 3 Thallus C–; gyrophoric and lecanoric acids absent............................................................................................................................ 5

3. Thallus K+ yellow; an unknown substance present ( RF close to atranorin in solvent C) present; pseudisidia cylindrical (0.2 × 0.1 mm)............................................................................................................... H. viridi-isidiatum P.F. Chen & L.L. Zhang (2022: 07) Thallus K–; the unknown minor substance absent; pseudisidia globular or cylindrical .................................................................... 4

4. Pseudisidia globular (0.1 × 0.1 mm) ......................................................................................................................... H. subglobosum Pseudisidia cylindrical (1.0 × 0.1 mm).......................................................... H. philippinum (Vain.) Aptroot & Lücking (2009: 43)

5. Thallus K+ yellow or K+ yellow then red, P+ orange-red; stictic or norstictic acids present ........................................................... 6 Thallus K–, P– or P+ yellow; stictic and norstictic acids absent........................................................................................................ 7

6. Thallus K+ yellow then red; norstictic acid present; pseudisidia irregularly cushion-shaped (0.4 × 0.2 mm).......... H. capilliferum Thallus K+ yellow; stictic acid present; pseudisidia cylindrical (0.3 × 0.1 mm)................................................................................. ......................................................................................................................... H. polyisidiatum P.F. Chen & L.L. Zhang (2022: 02)

7. Thallus P–; psoromic acid absent ....................................................................................................................................................... 8 Thallus P+ yellow; psoromic acid present.......................................................................................................................................... 9

8. Confluentic acid major; globular pseudisidia (0.06–0.12 mm in diam.).................................................................... H. tomentosum Perlatolic acid major; minute, irregular, soredia-like granular pseudisidia (0.05 × 0.05 mm in diam.) .............................................. ....................................................................................................................... H. granulare (Sipman) Aptroot & Lücking (2009: 43)

9. Pseudisidia cylindrical (0.5 × 0.1 mm).......................................................................................................................... H. echinatum Pseudisidia subglobose to irregularly cushion-shaped ..................................................................................................................... 10

10. Pseudisidia without pinkish or lilac pigments; subglobose (0.22–0.3 × 0.11–0.18 mm)............................................ H. glaucescens Pseudisidia with pinkish or lilac pigments; subglobose to mostly irregularly cushion-shaped ....................................................... 11

11. Thallus tightly appressed, medulla I–; pseudisidia irregularly cushion-shaped, pinkish, large (1 × 0.5 mm) ......................... H. weii Thallus loosely appressed, medulla I+ blue; pseudisidia whitsh subglobose or irregularly cushion-shaped, basally white, upper parts often lilac to lilac grey, small (0.1–0.45 mm in diam.)........................................................................................... H. lilacinum