Amaropostia stiptica

Cosmopolitan species most common on coniferous wood, with sessile, effused-reflexed to pileate basidiocarps 5 to 10 cm across and up to 2 cm thick, white, with 4 to 6 angular pores per mm having thin, lacerate dissepiments, tubes up to 0.8 cm long, and an intensely, persistently bitter taste.

Hyphal system monomitic; subicular hyphae densely interwoven, hyaline, thick-walled, 2 to 4 µm wide; pileipellis hyphae arranged more or less parallel with pale brownish intracellular pigment, 3 to 5 µm wide; both septate with clamp connections.

Cystidia absent, but scattered fusiform cystidioles 15 to 17 µm long and 4 to 4.5 µm wide occur in the hymenium.

Basidia clavate, 12 to 19 µm long, 4.5 to 5.5 µm wide, clamped at the base, 4-spored.

Spores cylindrical-ellipsoidal to oblong, smooth, hyaline, thin-walled, 4 to 5 µm long, 2 to 2.5 µm wide, with a slightly pointed apicular end, containing small guttules, inamyloid in Melzer's reagent.

Herbarium material available: JTP2529/25.