The genus Actidiographium L.N. Vasilyeva
Vasilyeva, Mikologiya i Fitopatologiya, Vol. 34 (6): 3-5. (2000)
by Eric W.A. Boehm
Vasilyeva (2000) established the monotypic genus Actidiographium L.N. Vasilyeva to accommodate a hysteriaceous fungus with pigmented uniseptate ascospores, reminiscent of those found in the genus Actidium, in the Mytilinidiaceae. But in Actidiographium orientale L.N. Vassilyeva, the didymospores are borne in a typical hysterothecium, that is non-conchate, and similar to that found in the hyalodidymosporous genus Glonium sensu Zogg (1962) (fide Psiloglonium). The pigmented didymospores measure 13.2-16.5 x 3-4 μm. As molecular data do not exist for this taxon, it is not clear at present whether the genus Psiloglonium should include pigmented didymosporous members, or whether the genus Actidium should include hysterithecioid members. Interestingly, in the original description, Vasilyeva (2000) reports that the ascomata are “fragile”, which hints at a thin-walled peridium characteristic of the Mytilinidiaceae.