Bird's Nest Fungus: Crucibulum laeve
Fruiting body cup-shaped, sessile, tough, persistent, 3-7 mm high, 3-6 mm wide, globose, becoming cylindrical, narrowed at the base, flaring at the mouth, the latter covered with an ochraceous, velvety, evanescent lid (epiphragm); outer surface roughened to finely wrinkled, buff-brown, inner surface smooth, pale grey to light-brown; peridioles (eggs) 1-2 mm broad, flattened, white to pallid, connected to the cup by a thin cord (funiculus).
Spores 7.5-10 x 4-6 µm, elliptical, smooth, nonamyloid.
Scattered to clustered on soil and woody debris, e.g. sticks, rotting plywood, etc.
Unknown, but too small and tough to be of culinary value.
Bird's nest fungi are represented by about six or seven species in the San Francsico Bay Area with Crucibuum laevae being one of the most likely to be encountered. It is distinguished by a buff-brown, thin-walled, flaring cup with a smooth interior, and pallid to white eggs that are connected to the cup via a thin cord. Related local bird's nests include species of Cyathus and Nidula, all of which have thicker-walled cups. In addition, the cups and peridioles of Cyathus species are darker (grey-brown to dark-grey), while Nidula species have peridioles which are embedded in a gelatinous matrix.