Ecology: Saprobic on the dead or dying sapwood of conifers, especially firs; growing in overlapping clusters on logs and stumps; spring through fall; widely distributed in North America. The illustrated and described collections are from Colorado.
Cap: Sometimes absent, or present as merely a folded-over edge, but usually present and semicircular to fan-shaped; 1–4 cm wide; up to 3 cm deep; thin; dry; fuzzy to hairy; with concentric zones of texture and color; shades of gray, with a purplish marginal zone when fresh; often hosting algae and becoming green.
Pore Surface: Purple when fresh, especially near the margin; fading to lilac or brownish with age; with 2–3 angular pores per mm; often tooth-like with age or in capless areas; not bruising.
Flesh: Whitish; tough and leathery.
Chemical Reactions: KOH negative on flesh.
Spore Print: Not verified by me; reported as white.
Microscopic Features: Spores 6–8 x 2–3 µm; smooth; cylindric to slightly allantoid; hyaline in KOH; inamyloid. Cystidia abundant; 20–30 x 5–10 µm; clavate to obutriform; smooth overall but developing distinctive crystalized apices; walls 0.5 µm thick; hyaline in KOH. Hyphal system dimitic; skeletal hyphae 4-9 µ wide, thick-walled, unclamped; generative hyphae 2.5–5 µm wide, thin-walled, clamped.