E-Flora BC: Electronic Atlas of the Flora of British Columbia

Summary:
Features include 1) resupinate growth on alder wood, often bent outwards forming a cap, 2) a soft, lax, light-weight consistency, 3) a cap that is at first white but soon turns pale beige brown or grayish, the cap surface undulating, slightly zoned, and finely velvety, 4) a spore-bearing surface that is white (yellowish when old), and tuberculate to pleated-veined, 5) spores that are allantoid, smooth, amyloid, and colorless, and 6) a monomitic hyphal system, the hyphae with large clamp connections that have a visible ''eye'', the basal hyphae somewhat thick-walled.

Plicatura nivea has been found in BC, WA, OR, ID, AB, MB, NB, NF, NS, NT, ON, PQ, SK, AK, CA, CT, MA, ME, MI, MN, MT, NH, NY, PA, and VT, (Ginns). It has also been found elsewhere in the northern hemisphere including Switzerland (Breitenbach), and Finland, France, Norway, and Sweden, (Eriksson).

Fruiting body:
resupinate to semipileate [bent outwards forming a half-cap], attached loosely to wood, forming patches 0.05-0.1cm thick, and several centimeters to decimeters across, often turned up at the margin and forming caps that extend up to 1-3cm from the wood, upper cap surface dark cream to orange-brownish, undulating, with a suggestion of zones, finely velvety; spore-bearing surface white (yellowish when old), tuberculate to plicate-venose [pleated-veined]; margin sharp and somewhat lighter than cap surface, (Breitenbach), resupinate to dimidiate, orbicular [circular] and some centimeters across, or confluent, loosely attached to wood, when living soft and lax, "when dried fragile and very light"; cap surface at first white (but turning grayish or pale beige brown), smooth, when very young or on the growing margin finely velvety under lens; spore-bearing surface white, turning yellowish when old and on drying, even orange or pale brown, smooth when young "but becoming distinctly and irregularly plicate" (not forming net-like pores), (Eriksson)

Microscopic:
SPORES 4-5 x 0.7-1 microns, cylindric, slightly allantoid, smooth, amyloid, colorless; BASIDIA 4-spored, 12-15 x 3-4 microns, cylindric-clavate, with basal clamp connection; CYSTIDIA not seen; HYPHAE monomitic, 2.5-4 microns wide, thin-walled to thick-walled, "in part incrusted with small crystals", septa with large clamp connections, (Breitenbach), SPORES 4-4.5 x 1 micron, allantoid, smooth, amyloid, acyanophilic, thin-walled; BASIDIA 4-spored, 12-18 x 3-4 microns, subcylindric - narrowly clavate, with basal clamp connection; CYSTIDIA none; HYPHAE monomitic, with large clamp connections (with a conspicuous ''eye'' at least in wider hyphae); subhymenial hyphae 2-3 microns wide, richly branched, thin-walled; tramal (subicular) hyphae 3-6 microns wide, over the clamp connection 8 or 10 microns wide, most hyphae straight, sparsely branched, with somewhat thickened walls, (Eriksson)