The North American Species of Pholiota

94. Pholiota schraderi (Pk.) Overholts, North Amer. Flora 10: 271. 1924.

Stropharia schraderi Peck, Bull. Torrey Bot. Club 32: 30. 1905.

Illustrations: Text figs. 493-496.

Pileus 5-8 cm broad, convex to nearly plane, pallid when young, ochraceous-buff when mature, dry, fibrillose, squamulose, or rimose-squamulose on the disc, squamules pale tawny in dried specimens. Context white; taste of radishes.

Lamellae adnate, whitish then brown, close, thin.

Stipe 2-4 cm long, 8-12 mm thick, squamulose and concolorous with the pileus below, white and mealy above, subequal. Veil forming a small white, lacerate, sometimes evanescent annulus.

Spores 6.5-8 (10) x 4-4.5 (5.5) µ, smooth, apical pore present but minute; shape in face view ovate to elliptic and many obscurely angular; in profile somewhat inequilateral to obscurely bean-shaped; color in KOH rather bright ochraceous to ochraceous tawny, in Melzer's reagent slightly duller; wall about 0.3 µ thick.

Basidia (21) 24-28 x 6-7.5 µ, 4-spored, when sporulating clavate or ventricose in lower half and cylindric above (obscurely urn-shaped), hyaline in KOH, in Melzer's reagent nearly hyaline. Pleurocystidia of two types: leptocystidia 40-60 (78) x 9-20 µ with a long narrow pedicel and clavate to utriform above or varying toward mucronate, content "empty", wall thin and smooth, or if thickened slightly then less than 0.5 µ thick; 2) chrysocystidia 28-44 x 7-12 µ, with refractive hyaline inclusion in KOH, in Melzer's the inclusion merely yellowish. Cheilocystidia 32-60 x 8-18 µ, similar to pleurocystidia (both types present). Caulocystidia present at stipe apex where a caulohymenium is present and both giant leptocystidia and chrysocystidia occur there as well as in the lamellar hymenium.

Gill trama of subparallel hyphae with colloidal content orange in Melzer's reagent, walls thin and hyaline, cells finally slightly inflated 3-8 µ or more diam.; subhymenium of non-gelatinous interwoven hyphae 3-5 µ diam., hyaline in KOH. Pileus context of inflated (8-15 µ) hyphae with thin smooth walls and "colloidal" content orange-red as revived in Melzer's reagent; cuticle of hyaline smooth narrow hyphae more or less appressed and no hypodermium differentiated; scales on pileus composed of fascicles of hyphae, the walls yellow in KOH, thin and smooth; cell content mostly "empty" but some with colloidal content; the cells inflated to sphaerocyst-like but varying in a single hypha to elongate. Clamp connections present. All hyphae inamyloid or dextrinoid as noted.

Habit, Habitat, and Distribution: On soil, District of Columbia, October. Type studied.

Observations: This species presents a problem in relationships because it is more closely related to Stropharia hardii and S. caesiispora than to any Pholiota known to us, yet it has bright ochraceous spores in KOH. Fresh spore deposits are needed to check the color. The deposit with the type collection is now near "snuff-brown" a yellow brown, but there is still a smoky tinge which could indicate that it was more purplish when fresh. In the light of the generic concept of Pholiota presented here we are forced to include the species as a Pholiota because of the spore features as described. It is related to Stropharia kauffmanii also, but in the latter the spores are definitely purplish. The germ pore of the spore in P. schraderi is clearly Pholiota-like.