Fruiting body annual or short-lived perennial, 1-4 cm broad, up to 0.5 cm thick, flattened to slightly convex, margin wavy, forming tiers of overlapping sessile shelves; surface hairy, zonate, whitish to light-grey, usually pale purple near the margin, in age sometimes greenish from colonizing algae; flesh leathery, thin, pale brown to purplish-brown.
Tubes single-seried, 1-3 mm long, pale brown; pores 2-4 per mm, circular to angular, at maturity frequently toothlike; purple when young, fading to brownish-purple.
Spores 4-6.5 x 2.5-3.0 µm, smooth, allantoid (curved cylindrical); spore print off-white.
In overlapping tiers on dead conifer wood, found year-round, shriveling in dry weather but capable of reviving; fresh fruitings emerging from late fall to mid-winter.
This attractive small, leathery shelf fungus makes up in numbers for its lack of size, often dominating on conifer logs. The white, hairy, zonate cap, usually with a purplish margin when young, and purple-tinged pores make it easy to recognize, although in age the pores may breakdown to form spines causing possible confusion with species of tooth fungi. Look-alikes include Schizophyllum commune, also with a whitish, hairy cap, distinguished by a "split gill" hymenium, and Fomitopsis cajanderi, an uncommon but larger, woody polypore that has a blackish-brown cap and pinkish pore surface. A closely related species, Trichaptum biformis, (aka Hirschioporus pargamenus), grows primarily on hardwoods.