The North American species of Psathyrella.

1972]

PSATHYRELLA

49

Basidia small, 4-spored, 18-26 x 6-7 ft, clavate, hyaline in KOH. Pleurocystidia
34-56 x 12-18 I, clavate to utriform, many almost as broad at apex as at ventricose
portion, rarely with a small to moderately large protuberance on or near apex,
smooth, thin-walled, mostly hyaline in KOH or Melzer's but some with brownish
dissolved content as revived in KOH. Cheilocystidia 10-17 t broad, clavate to
pedicellate. Caulocystidia mostly absent-a few at apex and similar more or less
to the pleurocystidia.
Pileus with a cuticle composed of a layer of vesiculose cells 2-4 deep with the
cells 15-40 pt broad or more, from this layer extend hyphae scattered or in fascicles
and 6-12(-16) A wide, the cells tubular to somewhat inflated and having dingy
ochraceous content as revived in KOH, the hyphae with walls thin and hyaline,
the cells disarticulating at times. Hyphae of the pileus context hyaline, cells
greatly inflated, lacking a colored zone (in KOH) beneath the cuticle. Clamp
connections present.
Type locality. Wildwood, Emmet County, Michigan.
Habit and habitat. Cespitose on a hardwood (maple) stump, Aug. 2, 1963.
Distribution. Michigan.
Observations. This species is close to P. subtruncatispora but is larger, and the
spores are more angular in face view.
Material examined. Michigan: Smith 33-1091, 15314, 25460, 32395, 43153,
67000 (Type), 67018, 71544, 80822.
15. Psathyrella lepidotoides A. H. Smith, sp. nov.
Pileus 1-4 cm latus, demum planus vel ad marginem leviter recurvatus et
appendiculatus, subspadiceus vel cinnamomeo-brunneus; sapor mitis; lamellae
pallidae demum sordide vinaceo-brunneae; sporae 8-10 x 4-5 p, ad basem truncatae; pleurocystidia 38-60 x 10-15 u, subcapitata vel late rotundata; caulocystidia
circa 75 x 18 A, clavata; hyphae epicuticularum intus incoloratae; fibulae adsunt.
Typus. Smith 73674 (MICH); legit prope Upper Priest River, Idaho.
Illust. Text Figs. 31-35.
Pileus 1-4 cm broad, obtuse when young, expanding to plane or margin finally
uplifted, surface with dingy appressed fibrils and squamules which are clay color
to duller ochraceous-brown (near "snuff brown") or over the disc in age the
patches "cinnamon-brown," margin appendiculate at first, becoming violaceousdrab as the spores mature. Context very fragile, odor and taste mild, with FeSO,
no color change.
Lamellae pallid brown becoming near "Natal brown" (dark vinaceous-brown),
close, nearly subdistant, adnate-seceding, edges even.
Stipe 3-5 cm long, 2-3.5 mm thick, equal, fragile, white, dotted with colored
fibrils from the veil, tawny at base in age.
Spores 8-10 x 4-5 I, smooth, apex truncate from a hyaline pore, shape in face
view wedge-shaped to corn-kernel-shaped (truncated at base also), in profile
obscurely bean-shaped to obscurely inequilateral or some almost elliptic, color in
KOH dull rusty brown and slowly darkening to an olive-brown or bister, in
Melzer's ochraceous-tawny to amber brown, wall about 0.3 U thick.
Basidia 4-spored, 15-20 x 7.5-9 u, subellipsoid, hyaline in KOH. Pleurocystidia
38-60 x 10-15 JL, neck 8-13 i wide, utriform to capitate; wall smooth, thin, hyaline,
content hyaline to weakly ochraceous in KOH, yellowish to faintly grayish (in a
few) in Melzer's. Cheilocystidia similar to pleurocystidia but smaller and some
fusoid-ventricose with subacute apex. Caulocystidia clavate, up to 75x 18 t,