The North American Species of Pholiota

60. Pholiota variabilispora sp. nov.

Illustrations: Text figs. 172-174.

Pileus 2-3 cm latus, convexus demum subplanus, glaber, viscidus, luteus demum argillaceus, ad marginem appendiculatus. Lamellae adnatae demum emarginatae, latae, confertae, pallidae demum sordide argillaceae. Stipes 3-4 cm longus, 3-4 mm crassus, subradicatus, pallide luteus, fibrillosus, sursum furfuraceus. Sporae (10) 11-15 x 7-10 µ, cum 2-3 poris. Pleurocystidia 30-38 x 10-15 µ, subcapitata. Specimen typicum in Herb. Mich. conservatum est; legit prope Echo Lake, Montana, C. H. Kauffman.

Pileus 2-3 cm broad, obtuse to convex, becoming broadly convex or nearly plane, surface glabrous and even, viscid when wet, "yellow ochre" to "ochraceous buff," becoming "clay-color" or darker when dried, margin at first appendiculate from fragments of the veil. Context whitish, thickish and pliant except along the margin, odor and taste not recorded.

Lamellae adnate, becoming emarginate to adnexed, broad (4-5 mm), close, pallid at first, finally "Dresden brown" (dark yellowish brown).

Stipe 3-4 cm long, 3-4 mm thick, base subrooting and with rhizomorphs, solid, pale yellow ("ochraceous buff"), fibrillose, apex furfuraceous, tubular; annulus not formed.

Spores (10) 11-15 x 7-10 µ, broadly ellipsoid to somewhat irregular, apex obscurely truncate or with 2-3 pores present near apex, dark tawny brown in KOH, thick-walled (0.5 µ), smooth.

Basidia two-spored, 22-26 x 7.5-9 µ, subclavate, hyaline in KOH. Pleurocystidia scattered, 30-38 x 10-15 µ, ventricose with subcapitate apex, dumbbell-shaped or simply fusoid-ventricose or apex subcapitate and below that equal to the base, hyaline, content homogeneous, thin-walled. Cheilocystidia 18-26 x 7-10 µ, fusoid-ventricose or apex subcapitate, thin-walled, hyaline in KOH.

Gill trama parallel to subparallel, subhymenium very thin, very slightly yellowish in KOH throughout, hyphae with inflated thin-walled cells. Pileus cutis a thin adnate gelatinous pellicle of appressed narrow hyphae hyaline in KOH but not different structurally from the context hyphae, the latter paler toward the gill trama. Clamp connections present.

Habit, Habitat, and Distribution: Gregarious in garden soil, Echo Lake, Montana, C. H. Kauffman, 1928. Known only from the type collection.

Observations: This species is likely to be mistaken for an Agrocybe in the field but the pileus cutis is not of inflated cells. Kauffman thought it was a Stropharia but the color of the spores is that of Pholiota. It is the only Pholiota known to us having spores with more than one germ pore on any of the spores. Some of the pleurocystidia are shaped like chrysocystidia but lacked the characteristic inclusion as revived in KOH.