The North American species of Psathyrella.

74

MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

[VOL. 24

35. Psathyrella ellenae A. H. Smith, sp. nov.
Pileus 1-3 cm latus, demum late convexus, glaber, cinnamomeus; lamellae
confertae, secedentes, sublatae, dilute brunneae demum rufo-cinnamomeae; stipes
2.5-4 cm longus, 1.3-3 mm crassus, cavus, fragilis, deorsum brunneus, sursum
albidus; annulus membranaceus; sporae 7-9 x 4-5 f; pleurocystidia 40-63 x 9-15 t/,
ad apicerum acuta; fibulae adsunt. Typus. Smith 58678 (MICH); legit prope
McCall, Idaho; Ellen Trueblood.
var. ellenae
Illust. Text Figs. 102-104.
Pileus 1.5-3 cm broad, convex, becoming broadly convex, glabrous, moist,
hygrophanous, watery cinnamon-brown and striatulate moist, fading to dingy
buff and when dried grayish; margin even and lacking any adhering veil remnants. Context almost paper thin, concolorous with surface, odor and taste not
distinct.
Lamellae close, moderately broad, adnate, seceding, pale dingy brown becoming "warm sepia" (dull dark reddish cinnamon), edges even.
Stipe 2.5-4 cm long, 1.3-3 mm thick at apex, base 2-4 mm thick, hollow,
fragile, brownish near the base, whitish over upper region, with a superior, thin
membranous annulus becoming grayish pallid in drying, with thin appressed
patches of veil fibrils scattered below the annulus at first, glabrescent in age.
Spores 7-9x 4-5 It, smooth, apical pore distinct and apex truncate, shape in
face view ovate to elliptic, in profile obscurely inequilateral to subelliptic, color
in KOH tawny-olive and slowly darkening to close to "bister," in Melzer's pale
reddish tawny, wall about 0.2 I thick.
Basidia 4-spored, 18-24x7-9 g, clavate, hyaline in KOH. Pleurocystidia
scattered, fusoid, 40-63 x 9-15 g, apex pointed and in KOH often with granules
adhering, hyaline to yellowish in KOH, wall thin (or in yellowish cystidia it is
refractive and 0.3-0.5 g thick as revived in KOH), cell content not distinctive.
Cheilocystidia mostly clavate to subvesiculose, 9-12 g wide, hyaline in KOH,
thin-walled.
Gill trama regular, hyphae interwoven and with inflated cells having ochraceous to brownish walls. Pileus trama dull tawny in KOH, hyphae with walls
smooth but thickened at and near the septa. Cuticle of pileus a layer of cells
2-3 deep with ochraceous walls smooth and not highly refractive, cell content not
distinctive. Clamps present.
Type locality. Above Boulder Lake, near McCall, Valley County, Idaho.
Habit and habitat. About 7,000 ft. elev. under spruce-fir.
Distribution. California, Idaho.
Observations. This is a very distinct species on the basis of spore size, apical
truncation of the spore, and their color in KOH along with the acute prominent
pleurocystidia, lack of an odor and the small size of the basidiocarps. It is named
in honor of its collector Mrs. Ellen Trueblood of Nampa, Idaho.
Of the European species considered, the description of P. xanthocystis Orton
reads much like that of P. ellenae, but it grew on a rotten birch log and has
cheilocystidia 65x28 p. P. jerdonii (Orton's type study) has spores 10-11x
5-5.5 t, with a very inconspicuous apical pore and a prominent apiculus. On the
basis of the spore features I would class P. jerdonii as related to P. caputmedusae.
Material examined. California: White 139. Idaho: Smith 58678 (Type).