Trichia affinis de Bary (1870: 336)

Moreno, G., Castillo, A. & Thüs, H., 2022, Critical revision of Trichiales (Myxomycetes) at the Natural History Museum London (BM), Phytotaxa 567 (1), pp. 1-20 : 17

Trichia affinis de Bary (1870: 336) .

Material studied:— URUGUAY. Tacuarembo: September 1928, Dr. G. Herter, B.M. 4147, [ BM001247524 = box] ( BM) .

This species is characterized by sessile yellowish sporocarps. The capillitium is composed of narrow (5–6 µm diam.) elaters. Under SEM we can see that it is surrounded by spiral bands with transverse striations and small spines, scarcely visible by LM. Free ends are pointed. Spore ornamentation has a net of variable morphology. The reticulum consists of wide discontinuous bands which form a broken mesh. The bands also are composed of a reticulum with smaller meshes.

Martin & Alexopoulos (1969) and Farr (1958, 1976) considered Trichia affinis as a synonymous species of T. favoginea (Batsh) Pers. and T. persimilis Karsten. , since “none of the differences supposed to separate this species is constant”.Although this group presents very similar characters, we follow the taxonomic treatment given by NannengaBremekamp (1991) and Lado (2005 –2021), who consider them to be different species.

According to our experience, the diameter of the capillitium is a good character to separate Trichia favoginea (8–10 µm diam.) from T. affinis and T. persimilis (4–6 µm diam.). Without this additional diagnostic character the separation of these latter two species can be difficult. For T. affinis , the presence of a capillitium with smooth or with small spines, spiral bands and spores with a broken reticulum is characteristic, while for T. persimilis , the presence of a capillitium with spiny spiral bands, and spores with a reticulum in the form of islets or patches of reticulum are typical. Also T. affinis differs from T. favoginea in that the latter does not have globose sporocarps, they are cylindrical and the spores are larger (13–15 µm diam.).