Confertotrama Nakasone & S.H. He, 2025

Confertotrama Nakasone & S.H. He , gen. nov. MB 843412 View Materials .

Etymology: The genus epithet “ Confertotrama ” refers to the compact and agglutinated context.

Basidiomes annual, resupinate, effused, closely adnate, subceraceous to crustose. Hymenophore smooth or tuberculate, yellow, orange to ochraceous, uncracked or densely cracked with age; margin determinate, abrupt or thinning out, sometimes loosening from the substrate, paler or concolourous with hymenophore. Context yellowish white, with compact and agglutinated texture. Hyphal system monomitic; all hyphae with clamps, colourless, thin- to slightly thick-walled, smooth, rarely branched, moderately septate. Gloeocystidia numerous, vesicular, tubular to subulate, large, thin- to thick-walled, smooth, often with yellowish contents, turning bluish black in sulphovanillin, embedded or slightly projecting beyond the hymenium. Basidia clavate, colourless, thin-walled, smooth, with four sterigmata and a basal clamp. Basidiospores ellipsoid, oblong ellipsoid to cylindrical, colourless, thin-walled, smooth or ornamented, distinctly amyloid, acyanophilous.

Type species: Confertotrama rugulosa (Berk. & M.A. Curtis) Nakasone & S.H. He

Notes: Larsson & Larsson (2003) indicated that Megalocystidium chelidonium , Boidinia macrospora , Gloeocystidiellum aspellum , Gm. compactum and Gm. formosanum formed a strongly supported lineage (/ chelidonium) in Stereaceae . Our phylogenetic analyses also recovered this lineage ( Fig. 1 View Fig ). Morphologically, these species have some similar characteristic features, such as yellowish basidiomes with compact texture, clamped generative hyphae and numerous large gloeocystidia with a positive sulphovanillin reaction. Basidiospores are reported as smooth in M. chelidonium and verrucose to indistinctly verrucose in the other species ( Wu 1996, Boidin et al. 1997). Since there are no other morphological characters that can be used to separate M. chelidonium from other species in this lineage, we treat the lineage as a single genus and propose the new generic name Confertotrama .