Leptotrochila P. Karst., Bidr. Känn. Finl. Nat. Folk 19: 245 (1871)
= Sporonema Desm., Annls Sci. Nat., Bot., sér. 3 8: 172, 182 (1847)
Leotiomycetes, Leotiomycetidae, Helotiales, Drepanopezizaceae
Saprobic or parasitic on the host plant in terrestrial habitat. Sexual morph: see Karsten (1871). Asexual morph: Conidiomata brown, pycnidial, solitary to gregarious or confluent, immersed, subglobose, unilocular, convoluted, glabrous. Ostiole absent, dehiscence by breakdown of apical wall in the middle part. Conidiomatal wall composed of thick-walled, pale brown to hyaline, compact cells of textura angularis in the basal and lateral part, becoming dark brown, larger cells towards the apex. Conidiophores arising from inner layers of the basal and lateral wall of conidiomata, hyaline, cylindrical or irregular, branched, septate, smooth-walled. Conidiogenous cells hyaline, enteroblastic, phialidic, cylindrical to lageniform, integrated or discrete, indeterminate, smooth-walled, with periclinal thickening at collarette zone. Conidia hyaline, fusiform to cylindrical or irregular, unicellular, smooth-walled, eguttulate.
Type species: Leptotrochila radians (Roberge ex Desm.) P. Karst., Bidr. Känn. Finl. Nat. Folk 19: 245 (1871)
Notes: More than 50 taxa have been described in Sporonema (http://www.indexfungorum.org/names/Names.asp). Limber (1955) studied and compared 18 species of Sporonema while Sutton (1980) gave a detailed generic description, but only the type species was treated in his study. The type species of Sporonema, S. phacidioides, was connected to Leptotrochila medicaginis (Fuckel) Schüepp (Sutton 1980) and therefore, Johnston et al. (2014b) synonymized Sporonema under Leptotrochila. Leptotrochila shares a similar form of conidia with phoma-like fungi, but it can be separated from the latter by its convoluted conidiomata. There is no molecular data available for asexual morph of Leptotrochila. Fresh collections are needed to better understand this genus and confirm the connection between Leptotrochila and Sporonema.
Distribution: Austria, Australia, Dominica, Canada, Czechoslovakia, Cyprus, India, Iraq, Italy, Israel, Kenya, Latvia, Malawi, New Zealand, Tanzania, UK, USA, Zambia (Sutton 1980).
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD (2020) Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.