Summary:
Phyllotopsis nidulans is recognized by the pale orange to yellow-buff, fuzzy caps that are more or less fan-shaped with a narrow area of attachment and grow in shelf-like groups on wood, and by the strong disagreeable odor. The close narrow gills are similar in color to the cap and the spore deposit is a shade of pinkish.

Cap:
2-8cm across, "more or less fan-shaped to scallop-shaped in outline", broadly convex to flat, margin at first inrolled; "pale orange to orange-buff, yellow-orange, or fading to buff"; "often covered at first with a white chamois-like cottony pubescence", densely hairy or fuzzy, dry, (Arora), 3-7cm wide and projecting 2-5cm, semicircular, conchate, kidney-shaped, or tongue-shaped, usually attached laterally but sometimes resupinate and attached by apex, margin inrolled for a long time, irregularly wavy; orange-yellow when moist, pale ocher-yellow when dry; finely tomentose-velvety, margin tomentose-villose [with woolly fine hairs], (Breitenbach)

Flesh:
colored like cap or paler (Arora), thin, tough, elastic; yellowish, (Breitenbach)

Gills:
close, narrow; "orange-buff to orange-yellow or pale orange", (Arora), extending radially-eccentrically toward attached part of cap, 20-30 reaching stem, 5-7 subgills between each pair of gills, broad; orange-yellow to rust-yellow, (Breitenbach)

Stem:
absent or rudimentary (Arora), absent or sometimes the cap drawn out into a stem-like extension, attached part often white strigose-tomentose (hairy-woolly), (Breitenbach)

Veil:
absent (Arora)

Odor:
"typically strong and disagreeable (like sewer gas or rotten eggs), but sometimes mild", (Arora), rather like rotten cabbage (Kibby), unpleasant, cabbage-like, (Breitenbach), sharp, very unpleasant, (Phillips), faint, pleasant, (Buczacki)

Taste:
sharp, very unpleasant, (Phillips), mild, mushroomy but rather unpleasant, (Breitenbach), bitter and unpleasant (Miller)

Microscopic spores:
spores 5-8 x 2-4 microns, sausage-shaped, smooth, inamyloid, (Arora), spores 5.1-6.7 x 2.1-3.3 microns, cylindric, kidney-shaped, to allantoid [curved sausage-shaped], smooth, iodine-negative, colorless; basidia 4-spored, 16-30 x 3.5-4.5 microns, narrowly clavate, with basal clamp connection; pleurocystidia and cheilocystidia not seen; clamps mentioned for cap cuticle and basidia, (Breitenbach)

Spore deposit:
"pale pinkish to apricot-pink to pinkish-brown", (Arora), cream-flesh-colored (Breitenbach), pinkish orange to creamy peach (Siegel)

Notes:
It has been found at least in OR (Kauffman), and CA (Desjardin). There are collections at the University of British Columbia from BC and AB. There are collections from the University of Washington from WA, OR, ID, AK, CA, MI, MS, NM, NY, OH, VA, and ON. The distribution was given by Breitenbach(3) as North America, Europe, Asia, and North Africa.

EDIBILITY

unknown (Arora)

Synonyms and Alternate Names:
Panellus nidulans (Pers.) Pilat
Pleurotus nidulans (Pers.: Fr.) P. Kumm.