Amylosporus campbellii (Berk.) Ryvarden

Norwegian J. Bot. 24: 217, 1977

Fruitbody: Basidiocarps annual, pileate, centrally to laterally stipitate, solitary or a few confluent, fleshy to soft corky and watery when fresh, without odour or taste, corky and light in weight upon drying. Pileus more or less circular, up to 15 cm in diam., 4 cm thick at centre, sometimes lobed, becoming thinner towards margin; margin undulating, obtuse to acute. Pileal surface cream when fresh, pinkish puff to pinkish brown with age or when dry, becoming pinkish buff to clay buff up on drying, azonate, smooth to rough. Pore surface cream when fresh, becoming buff when dry; pores angular, 2–3 per mm; dissepiments thin, lacerate. Context cream and watery when fresh, pinkish buff and corky when dry, up to 4 cm thick at centre; tubes buff and brittle when dry, up to 1 cm long. Stipe short and thick, buff and corky when dry, up to 1 cm long, 2 cm in diam.; pores decurrent on stipe.

Hyphal structure: Hyphal system dimitic; generative hyphae in context
and stipe bearing both simple septa and double or multiple clamp connections,
tramal generative hyphae mostly bearing simple septa; skeletal hyphae IKI–, CB–;
all hyphae unchanged in KOH.

Context: Generative hyphae dominant, hyaline, thin– to slightly thickwalled,
occasionally branched, 5–9 μm in diam.; skeletal hyphae common, thickwalled
with a narrow lumen to subsolid, frequently branched, flexuous, loosely interwoven, 3–8 μm in diam. (n = 40/2). Gloeoplerous hyphae occasionally present, frequently branched, flexuous, almost as thick as skeletal hyphae. Hyphae in stipe similar to those in context.

Tubes: Generative hyphae common, hyaline, thin-walled, rarely branched,
subparallel along the tubes, 3–8 μm in diam.; skeletal hyphae common to dominant, thick-walled with a narrow to wide lumen, frequently branched, flexuous, loosely interwoven, 3–9 μm in diam. (n = 40/2). Gloeoplerous hyphae frequently present, occasionally branched, flexuous, almost as thick as skeletal hyphae. Cystidia and cystidioles absent. Basidia clavate, with a basal simple septum and four sterigmata, 10–20 × 7–8.5 μm; basidioles in shape similar to basidia, but slightly smaller.