Trichia contorta (Ditmar) Rostafinski (1875: 259)

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 : 17-18

Trichia contorta (Ditmar) Rostafinski (1875: 259) .

= Trichia intermedia L.F. Čelakovský (1893: 38) .

Type (of Trichia intermedia ):— CZECH REPUBLIC. Bohemia prope Chudenice , 18 July 1884, L. Čelakovský, B.M. 2907, [box: BM001247525 ] ( BM!) .

Trichia contorta is characterized by its sessile and globose yellowish-brown sporocarps, with delicate peridium, elaters of capillitium with free ends pointed, and spores 11–13 μm in diameter, weakly ornamented with spines, which appear as pili under SEM. This typical ornamentation has repeatedly been observed previously e.g. by Rammeloo (1974), Neubert et al. (1993) and Wang & Li (2006). The macro- and microscopic characteristics of the type of T. intermedia studied in this paper coincide with those indicated for T. contorta by the previous authors, so we consider both species synonymous.

Trichia contorta was described by Ditmar (1813) as Lycogala contortum , who provided an excellent plate showing the fructifications and the capilicon formed by short elaters. The name Trichia contorta (Ditmar) Rostafinski may be invalid as it is a yonger homonym to T. contorta G.H. Otth. (1869: 62) . Based on the rather vaguely worded protologue and in the absence of access to type material, we follow Lado (2005 -2022) in considering T. contorta G.H. Otth. a doubtful name and in the interest of nomenclatorial stability continue the use of the long established name T. contorta (Ditmar) Rostafinski.

This species has been confused with Hemitrichia karstenii , from which it is clearly differentiated by its capillitium, formed by elaters with abundant free ends and spores that present an ornamentation formed by pili under SEM ( Rammeloo 1974), where interconnected pili can be seen, sometimes forming small reticula.

Two similar species to Trichia contorta with sessile sporocarps are T. varia (Pers. ex JF Gmel.) Pers. , which differs by its capillitium with spiral bands of irregular distribution, and T. alpina Meyl. , with a darker peridium, almost black, wider capillitium (5–10 μm in diam.), and larger spores (16–18 μm in diam.).