Xyloschistes

Xyloschistes is a fungal genus in the family Stictidaceae. It is monospecific, containing the single species Xyloschistes platytropa. This fungus is a wood-dwelling species that typically develops subcortically: a thin, whitish thallus forms beneath bark on old timber and dead pine branches, and small black fruiting bodies later break through to the surface. It is known from Finland, where it was first collected in the 1860s, and has also been reported from Spain. In Finland it is currently treated as endangered.

The species was described by William Nylander in 1868 as Xylographa platytropa, and the genus was later validated by Alexander Zahlbruckner to accommodate it. Modern multigene molecular studies place Xyloschistes firmly within Stictidaceae, close to Ingvariella (and near Cryptodiscus and Geisleria), and interpret its life mode as primarily saprotrophic—consistent with the weak or occasional lichenisation reported in older accounts.