Mycotaxon 82: 161. 2002.
Common Name: none
Synonyms: Clitocybe rosella M.M. Moser; Omphalina rosella (M.M. Moser) M.M. Moser ex Redhead, Ammirati & Norvell
Cap 0.5-2.0 cm broad, convex, becoming convex-depressed to infundibulate; margin incurved, then decurved to plane, sometimes appearing scalloped in age; surface glabrous, striate-sulcate to near the disc, vinaceous-brown, hygrophanous, fading to pinkish-tan, finally pale-tan; context thin, pallid; odor and taste mild.
Gills long decurrent, close to subdistant, pale-pink, fading to pinkish-cream, pallid at maturity; lamelluae up to three-seried.
Stipe 1.0-2.5 cm long, 1-3 mm thick, pliant, more or less equal, straight or bent, hollow in age; surface pruinose, becoming glabrous, colored like the cap, i.e. vinaceous to pinkish-brown, paler in age, often nearly tan; whitish tomentum at base; partial veil absent.
Spores 9.0-10.5 x 4.5-6 µm, ellipsoid, smooth, inamyloid, contents granular, hilar appendage prominent; spore print white.
Scattered to gregarious in open areas, e.g. along trails and in sparse grass, often in moss; fruiting along the coast from mid-winter to spring; exact distribution unknown but probably widespread; occasional, locally common.
Contumyces rosellus is a small, white-spored mushroom with an infundibulate cap, striate-sulcate margin, and decurrent gills. Its vinaceous to pinkish-brown hues are an important distinguishing feature. In age the cap may fade to a nondescript tan, but the gills and stipe usually retain some pinkish color. Other California Omphalinas (s.l.) include Loreleia postii (=Omphalina postii) with a bright-orange to reddish-brown cap, cream-yellow gills and a reddish-brown stipe; Omphalina ericetorum, (also known as Phytoconis ericetorum, but now called Lichenomphalia umbellifera), is the fruiting stage of a basidiomycete lichen, has a light-brown to yellow-brown cap, cream-colored gills, and red-brown to yellow-brown stipe; Omphalina epichysium (now known as Arrhenia epichysium) is the most somber-colored member of the group, the cap, stipe, and gills greyish-brown. Besides color it differs from the above in being truly lignicolous.
Bigelow, Howard E. (1985). North American Species of Clitocybe. Part II. J. Cramer: Berlin, Germany. 241 p.
Desjardin, D.E., Wood, M.G. & Stevens, F.A. (2015). California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 p.
Moser, M. (1950) Neue Pilzfunde aus Tirol. Ein Beitrag zu Kenntnis der Pilzflora Tirols. Sydowia 4: 84-123. (Protologue)
Redhead, S.A., Moncalvo, J.-M., Vilgalys, R. & Lutzoni, F. (2002). Phylogeny of Agarics: Partial Systematics Solutions for Bryophilus Omphaloid Agarics Outside the Agaricales (Euagarics). Mycotaxon 82: 151-168.
Redhead, S.A., Walker, G.R., Ammirati, J.F. & Norvell, L. (1995). Omphalina sensu lato in North America 4: O. rosella. Mycologia 87(6): 880-885.