The North American Species of Pholiota

171. Pholiota baptistii sp. nov.

Illustrations: Text figs. 371-373; 375-376.

Pileus 3-6 cm latus, convexus demum late convexus, subviscidus, glaber, sordide luteus, ad centrum subfulvus. Contextus luteus. Lamellae confertae, latae, adnatae, pallide luteae. Stipes 3-7 cm longus, 4-8 mm crassus, aequalis, sparse fibrillosus, sursum pruinosus, pallide luteus, deorsum subfulvus. Sporae 7-9 x 4-4.5 (5) µ. Pleurocystidia 45-82 x 7-18 µ, tenuitunicata, ad apicem obtusa vel late obtusa. Specimen typicum in Herb. Univ. Mich. conservatum est; legit prope Carney Lakes, Ada County, Idaho, Mr. C. F. D. Baptist, 15 Oct. 1956, (Trueblood 542)

 Pileus 3-6 cm broad, convex to nearly plane or with a low umbo, surface glabrous, slightly viscid, colors dull yellowish (ochraceous) or over center dull pale tawny, drying to pale yellow except for brownish disc. Context thin, yellowish, odor and taste not recorded.

Lamellae close, moderately broad, adnate to adnexed, pale yellowish and retaining this tone on drying, edges minutely fimbriate.

Stipe 3-7 cm long, 4-8 mm thick, equal or nearly so, thinly fibrillose; pruinose at apex and yellowish, drying greenish yellow; subfulvous below but color fading somewhat in drying; veil scarcely leaving an annular zone.

Spores 7-9 x 4-4.5 (5) µ smooth, wall slightly thickened (± 0.25 µ), rusty fulvous in KOH and more ochraceous in Melzer's reagent, (much paler than in KOH), apical pore distinct, some spores obscurely truncate; in face view oblong to elliptic, in profile slightly bean-shaped to elliptic, more rarely obscurely inequilateral.

Basidia 23-30 x 5-7 µ, 4-spored, clavate, ochraceous in KOH or paler, merely yellowish in Melzer's. Pleurocystidia 45-82 x 7-18 µ, narrowly to broadly fusoid-ventricose; walls thin or thickened, in some to 0.5 µ in ventricose part, smooth, apex obtuse to rounded, content homogeneous or some with some rod-like crystals, yellow to hyaline in KOH. Cheilocystidia 35-50 x 9-15 µ, and ellipsoid-pedicellate to clavate or subfusoid, thin-walled, hyaline or with yellowish content in KOH and in some the content amorphous and coagulated; some fusoid-ventricose cells like the pleurocystidia also present. Caulocystidia 40-65 x 10-20 µ ellipsoid pedicellate to clavate, rarely subfusoid, content often of rusty-ochraceous coagulated material; walls thin and hyaline to yellowish (in KOH).

Gill trama of parallel to interwoven hyphae with elongate cells 6-18 µ diam. (inflated at maturity); the walls thin, smooth, and yellowish to hyaline in KOH; subhymenium of gelatinous interwoven narrow hyaline hyphae. Pileus cutis a thin layer of narrow (2-4 µ) ochraceous hyphae with gelatinizing walls (layer becoming obliterated); hypodermium of floccose hyphae 5-12 µ diam. with coarse dark tawny, incrusting patches of pigment (layer dark orange-brown). Content hyphae inflated (8-18 µ ±) cells with thin smooth walls yellow to hyaline in KOH; hyaline to yellow oleiferous hyphae also present. All hyphae inamyloid. Clamp connections present.

Habit, Habitat, and Distribution: On conifer debris, Carney Lakes, Ada County, Idaho. C.F.D. Baptist, Oct. 15, 1956. (Trueblood 542, type).

Observations: This species is very close to P. tetonensis but is broadly convex, has voluminous caulocystidia and duller colors—more like P. spumosa. From the latter it differs in having a thin gelatinous pellicle which may become obliterated in age, the more rounded pleurocystidia, and the more erratic distribution of clamp connections—they were difficult to locate in some mounts and readily demonstrated in others. This last feature is probably of no taxonomic value but in the light of how the presence and absence of clamps is now being used generally as a character of value in Basidiomycete taxonomy such observations as recorded here are worth mentioning. The spores are the same size as for P. spumosa in Europe. The germ pore is broad enough so that with a 1.4 NA oil ob. the apex appears obscurely truncate in some spores. In some pilei the pleurocystidia were seen to fork as in P. tetonensis.