Clitocybe sclerotoidea (Morse) Bigelow
Mycologia 50: 46. 1958.

Common Name: none

Synonym: Tricholoma sclerotoideum Morse

• Pileus

  Cap 1.0-3.0 (4.0) cm broad, convex, expanding to nearly plane, with or without a low umbo; margin when young sometimes sulcate-striate or wavy, tomentose, incurved, in age decurved to plane, occasionally raised; surface dry, dull, glabrous or with appressed fibrils, the latter unevenly tan-brown over a cream to pale-grey ground color; context white, firm, up to 4.0 mm thick, unchanging when cut; odor not distinctive; taste mild.

• Lamellae

  Gills adnate, broadly notched to subdecurrent, close, becoming subdistant at maturity, relatively broad, cream-buff to dull tan; lamellulae up to 2-seried.

• Stipe

  Stipe 1.0-4.0 (6.0) cm tall, 4.0-8.0 mm thick, equal to clavate, solid, cream-colored; surface of apex fufuraceous, lower portion loosely covered with fibrils, sometimes inconspicuously pubescent, the base typically fused with other sporocarps, arising from a dirt-encrusted sclerotium; partial veil absent.

• Spores

  Spores 7.5 x 10.0 x 3.0-3.5 µm, ellipsoid to subfusoid (spindle-shaped), smooth, thin-walled, hilar appendage not conspicuous, inamyloid; spores creamy-yellow in deposit.

• Habitat

  In cespitose clusters, rarely solitary, growing from the rotted remains of Helvella lacunosa; fruiting from mid to late winter.

• Edibility

  Unknown, insignificant.

• Comments

  An unusual fruiting habit, on the decayed remains of Helvella lacunosa, helps distinguish this small drab mushroom. The typically clustered fruitings grow from a sclerotium, a mass of partially differentiated tissue which includes stipe remnants of a Helvella lacunosa. These are best seen by sectioning a sclerotium. Members of the Collybia racemosa, C. tuberosa group also fruit on decayed mushrooms, but are smaller, less robust, fruit from a grain-sized sclerotium, and do not occur with Helvella lacunosa. Collybia racemosa is particularly distinctive in having a stipe with slender side branches. Also compare with Inocybe geophylla, a similar-sized, whitish mushroom sometimes found under Monterey Pine (Pinus radiata) with Helvella lacunosa. The latter is separable by a spermatic odor, a dull-brown spore print, and a sparse fibrillose veil.

• References

  Bigelow, Howard E. (1982). North American Species of Clitocybe. Part I. J. Cramer: Vaduz, Liechtenstein. 280 p.
  Morse, E.E. (1943). Study of a new Tricholoma. Mycologia 35: 573-581.
  Trappe, J.M. (1972). Parasitism of Helvella lacunosa by Clitocybe sclerotoidea. Mycologia 64: 1337-1340.

• Other Descriptions and Photos
  • Fred Stevens: Clitocybe sclerotoidea (CP)
  • Fred Stevens: Clitocybe sclerotoidea (CP)
  • Boleslaw Kuznik -- Hunting for Mushrooms: Clitocybe sclerotoidea (CP)
  • Mushroom Observer: Clitocybe sclerotoidea (CP)
  • Arora (1986): p. 164 (D & CP)
  • Bigelow (1982): p. 191, fig. 98 (P)
  • Smith (1975): sp. 70 (D & CP)
  
  

  (D=Description; I=Illustration; P=Photo; CP=Color Photo)