The North American species of Psathyrella.

1972]

PSATHYRELLA

309

appearing truncate, shape in face view ovate (at times with a snout-like apical
third) to elliptic, in profile somewhat inequilateral to obscurely so, color in KOH
dark chocolate-color, in Melzer's reddish tawny, wall about 0.7-1 / thick.
Basidia 4-spored, 22-28x8-11 /u, hyaline, clavate. Pleurocystidia scattered
30-52x9-14 A, subfusoid to fusoid-ventricose, wall of neck at times flexuous,
apex subacute to obtuse, wall thin, smooth and hyaline, cell content not distinctive. Cheilocystidia similar to pleurocystidia. Caulocystidia fairly numerous,
resembling the cheilocystidia.
Gill trama of enlarged hyphal cells up to 18 / wide, perfectly hyaline in KOH.
Pileus having a cuticle of inflated cells 2-3 deep, the cells 10-25 / wide, walls
thin, smooth and hyaline, cell content not distinctive in either KOH or Melzer's.
Hyphae of pileus context perfectly hyaline in KOH. Scattered hyphae 8-10 p/
wide scattered over the surface of the cuticle. Clamps present.
Type locality. Knoxville, Tennessee.
Habit and habitat. Scattered in a lawn.
Distribution. Tennessee.
Observations. The spores with their tendency to taper to a snout-like apical
projection as in the typical species of Lacrymaria, their dark color in KOH, the
bluish-gray tones of the gills, and the silky pileus are distinctive. The species
is not closely related to members of subgenus Pannucia.
278. Psathyrella cubensis Murrill, Mycologia 10: 27. 1918.
Illust. Text Fig. 589.
Pileus 1-1.5 cm broad, campanulate to expanded, sometimes upturned at the
margin with age, surface glabrous, hygrophanous, sometimes rugose, reddish
brown to pale rosy isabelline; margin concolorous, striate becoming irregular or
fluted. Context thin and fragile.
Lamellae adnate to adnexed, broad, ventricose, rather crowded at first, pallid,
becoming dark purplish brown or almost black.
Stipe 3-5 cm long, 1 mm thick, filiform, glabrous, smooth, white and farinaceous at the apex, reddish below.
Spores 9-12(11-14) x7-9(9-11) /u, smooth, apical pore distinct and apex
narrowly truncate, shape in face view broadly ovate to broadly elliptic or (rarely
subglobose), in profile broadly elliptic to subovate, more rarely obscurely inequilateral, color in KOH dark date brown slowly becoming dark chocolate, in
Melzer's dull tawny-red, wall up to 1.5,u thick.
Basidia 2- and 4-spored, 18-24x 12-16 tu, clavate, hyaline in KOH. Brachybasidioles present. Pleurocystidia rare, 34-46 10-18 /u, fusoid-ventricose, apex
obtuse, scattered, thin-walled, smooth, hyaline, readily collapsing. Caulocystidia
not found.
Pileus cuticle a layer of thin-walled vesiculose cells lacking distinctive content
and 1-2 cells deep. Pileus trama merely dingy ochraceous in KOH. Clamps
present.
Type locality. Santiago de las Vegas, Cuba.
Habit and habitat. On clay soil in a banana field, June.
Distribution. Cuba.
Observations. There are many hyaline spores in mounts of the hymenium, but
the shocking experience was to find more hyaline spores deposited on the apex of
the stipe than dark brown ones. This would seem to indicate partial albinism in
the basidiocarp or that the genetic control of spore color was somehow breaking
down.