Cystoderma carcharias var. fallax (
Mycological Progress 8(1): 68. 2009.
Common Name: none
Synonym: Cystoderma fallax A.H. Sm. & Singe
Cap 1.5-4.0 cm broad, convex, expanding to plano-convex, sometimes with a low umbo; margin at first slightly inrolled and fused to a sheathing stipe, then decurved, occasionally appendiculate, finally nearly plane; surface covered with superficial granules or small erect scales, most of which weather away in age leaving only a scattering of powdery granules; color: rusty-brown to yellow-brown; flesh thin except at the disc, colored like the cap; odor and taste mild.
Gills adnexed, close, narrow, white, cream to pale yellowish.
Stipe 2-6 cm long, 3-7 mm thick, more or less equal, solid to stuffed; the apex smooth to appressed fibrillose, cream to pale yellow; below the ring, a sheathing, granulose, rusty-brown to ochraceous-brown veil, at maturity forming a persistent, membranous, median to superior, flaring ring, pallid on the upper surface, the lower surface like the cap and lower stipe.
Spores 4-5.5 x 3-4 µm, broadly elliptical, smooth, amyloid; spore print white.
Solitary, scattered, or in small clusters on moss, rotten logs, and needle duff in conifer woods; fruiting after the fall rains.
One of our prettiest small mushrooms, Cystoderma carcharias var. fallax can be fairly common in our area, although in many years it is an exceptional find. Distinctive with its rusty-brown to ochraceous-brown cap, adorned with easily rubbed off granules, it is unlikely to be confused with any other white spored fungi except other Cystoderma species. A close relative, Cystoderma amianthinum, is similarly colored and ornamented, but lacks a well-developed veil and persistent ring.
Desjardin, D.E., Wood, M.G. & Stevens, F.A. (2015). California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 p.
Saar, I., Põldmaa, K. & Kõljalg, U. (2009). The phylogeny and taxonomy of genera Cystoderma and Cystodermella (Agaricales) based on nuclear ITS and LSU sequences. Mycological Progress 8(1): 59-73.
Smith, A.H. (1949). Mushrooms in their Natural Habitats. Sawyer's Inc: Portland, OR. 626 p.
Smith, A.H. & Singer, R. (1945). A monograph of the genus Cystoderma. Pap. Michigan Acad. Sci. 30: 71-124.