The North American Species of Pholiota

65. Pholiota johnsoniana (Pk.) Atkinson, Studies Amer. Fungi, p. 153. 1900.

Agaricus johnsonianus Peck, New York State Cab. Ann. Rept. 23: 98. 1872.
Stropharia johnsoniana (Pk.) Peck, New York State Mus. Ann. Rept. 41: 84. 1888.

Illustrations: Text figs. 484-485.

Pileus 3-10 cm broad, broadly convex or nearly plane, yellowish or ochraceous, or yellow in the center and white on the margin, glabrous or at times with small appressed squamules at the center, dry, sometimes purple stained, margin striatulate when moist. Context white, thick at the center, thin on the margin; taste agreeable, nutty.

Lamellae adnate or sinuate-adnate or nearly free, white then rusty-brown, close, narrow (2-5 mm broad).

Stipe 7-10 cm long, 8-15 mm thick, light colored, glabrous, apex slightly striate, equal. Veil forming a thick white, persistent cottony roll on the stipe, easily breaking and then disappearing.

Spores cocoa-color in deposit (type collection), 5.5-7.5 x 3.5-4 x 4-5 µ, smooth, many compressed slightly, apical pore minute and apex not truncate; shape in face view ovate to elliptic, many almost triangular-ovate; in profile varying from bean-shaped to somewhat inequilateral; color in KOH near ochraceous tawny to merely ochraceous, about the same color in Melzer's reagent; wall about 0.25 µ thick.

Basidia 4-spored, 20-25 x 5.5-7 µ, clavate, hyaline in KOH in Melzer's reagent ochraceous. Pleurocystidia abundant, 18-23 x 7-12 µ, clavate to clavate-mucronate, with a hyaline refractive inclusion usually near the apex (they are typical chrysocystidia) smooth, thin-walled, the refractive inclusion merely yellowish in Melzer's reagent. Cheilocystidia similar to pleurocystidia. Caulocystidia none except for those in caulohymenium at stipe apex and these similar to the pleurocystidia.

Gill trama of subparallel thin-walled smooth hyphae with cells 6-15 µ broad or more (when fully inflated), hyaline to yellowish in KOH and pale reddish brown in Melzer's reagent but soon fading to yellowish; subhymenium not sharply distinguished from the body of the gill trama (the hyphae merely narrower). Pileus cutis a pellicle of hyaline smooth thin-walled narrow (2-4 µ) subgelatinous hyphae; hypodermial region not showing distinct differentiation. Context hyphae hyaline to yellowish revived in KOH, thin-walled, interwoven the cells inflating to 15 µ, or more finally. All hyphae inamyloid. Clamp connections none.

Habit, Habitat, and Distribution: On soil, in pastures, and in leafmold in woods, New York, North Carolina and Michigan, September. (As reported in the literature). Type studied.

Observations: Singer (1963) preferred to place this species in Stropharia and indeed there is ample justification for this. The cocoa-colored spores can be used as a justification for placing this species in either Pholiota or Stropharia, however. This is an indication of the intermediate position of the species. We decided to place it in Pholiota because of the very minute apical germ pore of the spores. Also, its natural place in the classification of Agaricales appears to be here among the stropharioid Pholiotae.