The North American Species of Pholiota

35. Pholiota kalmicola (Murr.) comb. nov.

Hebeloma kalmicola Murrill, North Amer. Fl. 10: 218. 1917.

Illustrations: Text figs. 72-74.

Pileus 2.5-3.5 cm broad, convex expanding to convex-depressed, not umbonate, uniformly yellowish white to cream colored, surface moist, slightly viscid, subglabrous, margin entire and concolorous, not striate. Context thin; odor none, taste slightly unpleasant.

Lamellae adnexed or sinuate, yellowish white to dirty white, very broad, moderately close, thin, entire and concolorous on the edges.

Stipe 5 cm long, 3 mm thick, slender, cylindric, equal, fibrillose, slightly darker than the pileus, hollow.

Spores 7-9 x 4-5 µ (9-12 x 5-6 µ), smooth, apex differentiated much as in P. serotina, shape in face view oblong to elliptic for 4-spored basidia, suboblong and obscurely angular for those from 2-spored basidia, in profile oblong to subelliptic; tawny or paler in KOH and about the same color in Melzer's reagent; walls 0.3-0.4 µ thick.

Basidia 17-21 x 6-8 µ, 4-spored and 2-spored, utriform, hyaline to yellow in KOH and in Melzer's reagent. Pleurocystidia scattered, 18-26 x 8-14 µ clavate, clavate-mucronate or broadly fusoid-ventricose, wall smooth, thin, hyaline, content hyaline to yellow in KOH and homogeneous (with aspect of chrysocystidia but lacking the inclusion as revived in KOH). Cheilocystidia similar to pleurocystidia or varying to vesiculose-pedicellate. Caulocystidia not studied.

Gill trama a central hyaline strand of floccose hyphae with cells smooth, thin-walled, inflated, and hyaline in KOH; subhymenium a broad gelatinous band of narrow (2 µ) hyaline branched hyphae. Pileus trama of hyaline floccose interwoven hyphae with inflated thin-walled smooth cells; above it a hypodermial region of bright rusty brown (in KOH) incrusted inflated cells and above this a gelatinous pellicle of yellow, narrower (4-7 µ) nearly smooth tangled hyphae. Clamp connections present. All hyphae inamyloid.

Habit, Habitat, and Distribution: Gregarious on a much-decayed mossy stump of Kalmia latifolia, Virginia, October. Type studied.

Observations: The spore size as given in Murrill's original description is slightly erroneous. The spores, gill trama, pileus trama and habitat on wood make this a typical "Flammula" of the Friesian classification. The portion of the type examined was in part sterile, which accounts for the pale gills. The stature is much like that of Pholiota myosotis, but no chrysocystidia were found. The cystidia which are present are more properly classed as leptocystidia. The species is most closely related to P. scrotina by its peculiar spore feature but has much wider gills. Both show the same pattern of variation in spore size and shape. In P. serotina, however, the subhymenium is poorly defined whereas in P. kalmicola it is more highly developed than in any other Pholiota known to us.