The North American Species of Pholiota

16. Pholiota curcuma var. curcuma (Berk. & Curt) comb. nov.

Agaricus curcuma Berkeley & Curtis, Ann. & Mag. Nat. Hist. II; 12: 421. 1853.
Phaeomarasmius curcuma (Berk. & Curt.) Singer, Schw. Zeitschr. Pilzk. 34: 60. 1956.

Illustrations: Text figs. 22-23.

Pileus 10-20 (35) mm broad, obtusely conic when young, expanding to broadly campanulate to convex or finally nearly plane, surface dry and appearing echinate (with minute erect squamules), toward margin appearing granular and squamules poorly formed, color bay to rusty-fulvous ("bay" becoming "amber-brown") finally ochraceous tawny, evenly colored. Context thin, lax, pale dingy ochraceous when mature, odor and taste none; olive with FeSO4.

Lamellae close, moderately broad, bluntly adnate, dingy ochre-yellow scarcely changing, edges concolorous with faces. Stipe 1.5-3 cm long, about 1.5 mm thick at the slightly enlarged apex, dingy brownish and in age becoming darker rusty brown from the base upward, thinly covered by appressed buff-colored fibrils from a very thin veil.

Spores 7-9 x 3.5-4.5 (5) µ, smooth, with a minute apical pore, in profile slightly bean-shaped to obscurely inequilateral, in face view elliptic to ovate, tawny in KOH and paler and dingier in Melzer's sol.

Basidia 4-spored, 18-23 x 5-7 µ, narrowly clavate to subcylindric when sporulating, yellowish hyaline in KOH. Pleurocystidia none. Cheilocystidia 26-40 (50) x 8-15 µ, utriform, broadly fusoid-ventricose, subclavate, thin-walled hyaline to yellow from pigment in the walls, smooth.

Gill trama of gigantic hyphal cells with thin non-gelatinous smooth walls yellow in KOH, the cells 10-25 µ, wide and greatly elongated; subhymenium indistinct. Pileus cutis a trichodermium of hyphae with inflated cells up to 20 µ or more in diam., the walls of the cells thin but yellow in KOH and with coarse patches of rusty cinnamon pigment incrusting them; hyphae of subcutis narrower and some tubular but with the walls mostly heavily incrusted also. Context hyphae thin-walled, smooth, ochraceous in KOH. All hyphae inamyloid. Clamp connections present.

Habit, Habitat, and Distribution: Solitary to scattered on aspen logs during the summer and fall, South Carolina, Michigan, and Wyoming.

Observations: The features which at once distinguish this species from P. granulosa are the mostly hyaline utriform to broadly ventricose cheilocystidia and the very coarse pigment incrustations on the cells of the pileus trichodermium. The germ pore is minute but readily visible especially on the larger spores. The cells of the trichodermial hyphae vary from narrowly ventricose to subglobose, and the terminal cell is often elliptic to clavate—not fusoid—ventricose. Phaeomarasmius suberinaceellus Singer is indicated as having clavate cheilocystidia and the North American material he cites more than likely belongs in P. granulosa as this is the common species around Douglas Lake, Mich. P. curcuma is distinct because of the very heavy dark colored pigment incrustations of the trichodermial hyphae.

Material Examined: IDAHO: Smith 54130, 65985, 73450, 73451, 73452. MICHIGAN: Smith 33-971, 31. WYOMING: Smith 34429.