The North American Species of Pholiota

93. Pholiota sola sp. nov.

Illustrations: Text figs. 186-188; pl. 40b.

Pileus 2-3 cm latus, obtusus demum obtuse campanulatus, vel subplanus, fibrilloso-sqamulosus; squamulae luteo-brunneae; contextus subspadiceus. Lamellae decurrentes, confetae, latae, pallide subluteae demum subfuscae. Stipes 6-8 cm longus, 7-8 mm crassus, intus subolivaceus, extlus pallide Iuteus, deorsum squamosus; squamae recurvatae. Sporae 8-10.5 x 4.5-5.5 µ. Pleuro-pseudocystidia 3-9 µ latae. Cheilocystidia 35-56 x 6-8 x 2.5-3 µ fusoide-ventricosa et proliferata. Specimen typicum in Herb. Univ. Mich. conservatum est; legit prope Tahquamenon Falls State Park, 2 Aug. 1951. Smith 37424.

Pileus 2-3 cm broad, obtuse with an incurved margin, expanding to obtusely umbonate, or nearly plane and the umbo obsolete, surface appressed fibrillose-squamulose, the scales most distinct along the margin, ground color between avellaneous and cinnamon buff, squamules and fibrils "tawny-olive" to "cinnamon-brown." Context near "Saccardo's umber" (dark yellow-brown), fading; taste and odor none.

Lamellae decurrent, close, moderately broad, "cream-buff" when young, finally earth-brown from the spores.

Stipe 6-8 cm long, 7-8 mm thick, equal, tubular, dingy pale olive-yellowish inside, exterior near apex yellowish (paler than gills) yellow less evident toward the base, covered to the apical annular zone with scattered tawny-olive squamules concolorous with pileus over all except the apex.

Spores 8-10.5 x 4.5-5.5 µ, smooth, apical pore none, shape in face view oblong to elliptic, some obscurely angular, in profile more or less bean-shaped, in KOH tawny-cinnamon and about the same color in Melzer's reagent.

Basidia 30-54 x 6-9 µ, 4-spored, clavate, hyaline and homogeneous in KOH or some with granular pale ochraceous content, in Melzer's reagent a fair number with very dark yellow-brown to bister granular-amorphous content causing them to stand out prominently in mounts in Melzer's. Pleurocystidia present as crooked filaments with granular content, yellowish in KOH or in Melzer's with very dark yellow-brown granular to amorphous content and often seen connected to oleiferous hyphae with the same content, the cells 3-9 µ broad and length extremely variable. Cheilocystidia versiform: 1) subcylindric to subfusoid, walls often flexuous, 25-44 x 4-7 µ; 2) ventricose at base and proliferated into a narrow crooked neck, 35-56 x 6-8 x 2.5-3 µ; 3) fusoid-ventricose with wavy neck and obtuse apex, 24-35 x 5-8 µ; some cystidia branched at apex, walls hyaline or toward cap margin many with pale cinnamon brown walls in some part or overall. Caulocystidia 45-76 x 6-18 µ clavate to cylindric, walls brown, occurring in tufts.

Gill trama of parallel hyphae 4-10 µ broad, hyaline in KOH and thin-walled; subhymenium cellular. Pileus cutis with an epicutis in the form of a tangled turf of brown-walled hyphae smooth to slightly incrusted, ochraceous in KOH, dark red-brown in Melzer's reagent; arising from a layer of appressed yellow-brown hyphae. Content hyphae hyaline to yellowish in KOH, closely interwoven. Clamp connections present. Cutis hyphae weakly dextrinoid (reddish cinnamon).

Habit, Habitat, and Distribution: On humus, Michigan, August, Smith 37424, type.

Observations: This species is characterized by its avellaneous to cinnamon-buff colors, olive to brown fibrillose scales on the cap, tawny-olive scales on the stipe, "pseudocystidia" and relatively large spores.

The features of this species are peculiar. The hyphae of the laticiferous system in some instances were seen to produce basidia-many of which were seen to bear immature spores; These basidia were often of indefinite length in that they could be traced back into the gill trama without finding a septum. The cheilocystidia are not typical of any Inocybe known to us though the spores and the anatomy of the pileus cutis suggest that genus. No cystidia were found over the basal or lower part of the stipe. Since the aspect of the basidiocarp is that of a Pholiota and the cheilocystidia are not out of line for that genus as far as shape is concerned, we describe the species here.