Microthecium masonii (Kirschst.) Y. Marin, Stchigel, Guarro & Cano comb. nov.

Ceratostoma masonii Kirschst., Trans. Br. mycol. Soc. 18: 306. 1934. [Basionym]

≡ Persiciospora masonii (Kirschst.) P.F. Cannon & D. Hawksw., J. Linn. Soc., Bot. 84: 135. 1982.

Notes.

Microthecium masonii is characterized by ostiolate ascomata and ellipsoidal to fusiform, faintly striate-reticulate ascospores. The same type of ascospore ornamentation is also observed in Mi. micropertusum, but this latter species is easily distinguished by the presence of inconspicuous ridges forming a very coarse reticulum and a phialidic asexual morph.