The Botany of Iceland - 01.12.1932, Qupperneq 102

550
POUL LARSEN
The face of the gills bears true cystidia, these are fusiform, 50—10
with yellow granular contents.
Psathyra Fries.
578. P. spadiceo-grisea (Schaeffer) Fries, Hym. Eur., p. 306.
Lagarlljót, Reykjahlíd and Norðtúnga [P. L.]. — In copses of Betula
pubescens and Betula nana.
Pileus 3—4 cm broad, convex, + gibbous, with striate-sulcate margin,
flesh thin and brittle, hygrophanous, reddish-hrown when moist (j 3),
fuscous when dry (k 4). — Stipe shiny white, rigid, flexuose, fragile,
hollow, distanlly and slightly floccose above. — Gills narrow, crowded,
broadly adnate, pale greyish-brown, then black with white frayed edge.
— Spores dark-brown, 8—9X5/1, sometimes faintly curved. — Cystidia
short, cylindrical, swollen in the middle, 30—40X10 /i.
579. P. gossypina (Bulliard) Fries, Syst. Myc. I, p. 310.
Agaricus gossypinus Bulliard, 1. c., t. 425. f. 2.
Hallormstaðir [P. L.]. — On the ground among twigs and branches
in birch copses.
Pileus 2—4 cm broad, convex, gibbous with pellucidly striate margin,
browm (h 2) when moist, grey (h 4) when dry, the remains of the white
veil hanging from the margin. — Stipe cylindrical, shining, white, covered
with a white frayed coating, hollow, brittle. — Gills ventricose, broadly
adnate, crowded, at first grey then dark-brown. — Spores brown, ellip-
soidal, 8—9X4—4.5 /i. — Cystidia fusiform, drawn out above into a
short point.
580. P. bifrons (Berkeley) Fries, Monographia Hym. II, p. 347.
Agaricus bifrons Berkeley, English Flora V, p. 114.
Hallormstaðir [P. L.]. — Under willows in bogs.
Pileus up to 3 cm broad, obtusely conico-campanulate, flesh thin or
skin-like, rugose and pitted at the margin, which is at flrst covered by
a thin fugaceous veil, hygrophanous, reddish-brown (j 3) when moist,
alutaceous (k 1 to j 1) when dry. — Stipe cylindrical-conical, rigid, brittle.
hollow, white, mealy and floccose above, covered with projecting hairs at
base. — Gills ascending, adnate, pale grey, then dark-brown, but white
at the edg'e. — Spores ellipsoidal, smoofh, dark-brown, 13X7 /i. — Cj7-
stidia elongate-conical with obtuse apex, 40—50 /i long.
Psathyrella Fries.
581. P. prona Fries, Hym. Eur., p. 315.
Agaricus pronus Berkeley et Broome, No. 924.
Reykjavík [P. L.]. — Roadside by Elliðaá.
Pileus 1—1.5 cm broad, hemispherical, flesh thin, margin striate,
sericeo-pulverulent, brown (h 3) when moist, livid (e 2) when dry. —