Linosporopsis Voglmayr & Beenken, Mycol. Progr. 19(3): 212 (2020)

Index Fungorum number: IF 833894; Facesoffungi number: FoF 15043

Etymology – referring to its similarity to Linospora.

Mycelium in dead overwintered leaves, strongly bleaching the host tissue. Pseudostromata immersed in dead leaves, reduced, forming a distinct black clypeus-like structure on both sides of the leaf above and below the single perithecium, composed of dark brown, septate hyphae in dead host epidermis cells and forming a textura epidermoidea-intricata. Ascomata perithecial, scattered, solitary, immersed, (sub)globose, with a central apical papilla. Peridium thin, composed of hyaline, thin-walled, pseudoparenchymatous to prosenchymatous cells forming a textura angularis. Hamathecium of unbranched, thin-walled, hyaline, septate, apically tapering paraphyses. Asci unitunicate, long-cylindrical, with a short stipe, with an indistinct, inamyloid or slightly amyloid apical apparatus, containing 8 ascospores in a single fascicle. Ascospores long-filiform, hyaline, smooth, and without visible septa, sheath or appendages. Asexual morph: unknown.

Notes – Within Xylariales, the genus is distinctive by long filiform ascospores without obvious septa and by single, scattered clypeate perithecia, which are embedded in a reduced pseudostroma immersed in dead, strongly bleached leaf tissue. The often large, bleached patches on the leaves are highly distinctive, especially when the leaves are wet. Unlike the large, amyloid, wedge-shaped apical apparatus of most Xylariaceae sensu stricto, that of Linosporopsis is indistinct, usually unnoticeable, and only occasionally slightly amyloid (observed only in a single accession each of L. ochracea and L. magnagutiana).

Type species Linosporopsis ischnotheca (Desm.) Voglmayr & Beenken.