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.
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)
Notes: 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).
Habitat and Range
Habitat
principally on dead branches and stems of small diameter of Alnus species; associated with a white rot; Abies (fir), Acer (maple), Alnus (alder), Betula (birch), Populus, Salix (willow), Tilia (basswood), (Ginns), on dead wood of Alnus viridis (Green Alder), on falling and standing trunks and fallen and attached branches, at montane and subalpine elevations, (Breitenbach for Switzerland), on dead, hanging or fallen branches, standing or fallen dead trunks etc. of Alnus spp., rarely on other hardwoods, (Eriksson)