Tyromyces angulatus Soares & Ryvarden
MycoBank number: MB 821090 Facesoffungi number: FoF 03643
Etymology: angulatus (Latin) = the name refers to the angular pore surface.
Holotype: URM 89352
Basidiomata annual, resupinate, adnate, finely tomentose, up to 4 mm thick, soft when dry. Margin narrow, white (2B). Pore surface pale ochraceous to cream (5E−6F), pore angular, 2–4 per mm, dissepiment thin and entire, tubes concolorous, up to 1 mm deep. Context up to 0.1 mm, cream (3C) and almost absent in some places. Basidiospores subglobose to broadly ellipsoid, 3–4 × 1.8–2 μm, smooth, thin-walled, IKI-. Basidia clavate, with four sterigmata, 7.5–12.5 × 5–7.5 μm. Hyphal system dimitic, generative hyphae clamped, thin-walled, 3–5 μm in diameter; skeletal hyphae dominant, thick-walled, hyaline, 4.5–5 μm in diameter. Cystidia absent, cystidioles fusiform to mammillate, 10.5–18.2 × 5–7.5 μm.
Material examined: BRAZIL, Pará: Portel, Floresta Nacional de Caxiuanã, on dead hardwood, 1° 42’ 24.09” S and 51° 27’ 34.3” W, August 2013, A. Soares, AS 661 (URM 86923, holotype; O, isotype); August 2013, A. Soares, AS 656 (URM 86351). GenBank numbers LSU:KY980664.
Notes: Tyromyces angulatus was originally assigned to Diplomitoporus because of its typical dimitic hyphal system, resembling D. allantosporus Ryvarden & Iturriaga due to the angular pores, i. e. 2–3 per mm. However, the type specimen of the new species did not cluster in the same clade of D. flavescens (Bres.) Domanski, the type species of Diplomitoporus, but in the “Tyromyces clade”. Basidiomata of Tyromyces are dominated by clamped generative hyphae, while T. angulatus deviates from that concept by its dominance of skeletal hyphae mixed with few clamped generative hyphae. It is therefore surprising that the phylogenetic analyses place it in the “Tyromyces clade”, showing that hyphal system is more variable than previously assumed.