The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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102. Psathyrella franklini A. H. Smith, nom. nov.
Gymnochilus caespitosus F. S. Earle, Inf. An. Estac. Centr. Agron. Cuba 1: 240. 1906.
Hypholoma caespitosum (Earle) Morgan, Jour. Mycol. 14: 29. 1908.
Drosophila caespitosa (Earle) Murrill, Mycologia 10: 67.1918.
Illust. Text Figs. 253, 254.
Pileus 3-5 cm broad, convex then expanded, glabrous, faintly striate, hygrophanous, cinnamon-brown at first, becoming pale gray, darker in the center.
Context thin and pallid.
Lamellae adnexed, dirty white at first, becoming dark brown (cinnamonbrown when dried).
Stipe 6-12 cm long, 4-6 mm thick, rather stout, hollow, flocculose, white, the
veil white, appendiculate and evanescent.
Spores 6-7.5 x 4-5.5 A, smooth, with a broad but obscure apical pore causing
apex in many to appear truncated, shape in face view elliptic to slightly ovate, in
profile subelliptic to obscurely bean-shaped, color nearly hyaline to weakly
ochraceous in KOH but on standing becoming clouded somewhat with chocolategray, in Melzer's pale reddish tan, wall about 0.2 A thick.
Basidia 4-spored, hyaline in KOH, 17-20 x 7-8. Pleurocystidia scattered
35-45 x 9-15 A, fusoid-ventricose, apex broadly rounded, thin-walled, readily
collapsing, smooth or with mucilaginous material adhering over upper part of
neck or apex, content not distinctive. Cheilocystidia similar to pleurocystidia
but varying to elliptic, clavate and vesiculose, 30-40 x 10-20 >.
Gill trama regular, the hyphae with greatly inflated cells, the walls thin and
the cells tending to remain collapsed, weakly dingy ochraceous in KOH. Pileus
with a cuticle of vesiculose cells (reviving poorly and other details not reliably
ascertained). Hyphae of the trama in the subcuticular region tawny in KOH and
apparently with smooth walls. Clamp connections present.
Type locality. Santiago de las Vegas, Cuba.
Habit and habitat. Cespitose on a stump in a garden.
Distribution. Known only from the type locality.
Observations. The species appears to be closely related to P. hymenocephala
but has pleurocystidia.
Subsection Subacutae A. H. Smith, subsect. nov.
Sporae 5-10 t longae; pleurocystidia acuta vel obtusa. Typus. Psathyrella
delineata.
Key to the Species of Subsection Subacutae
1. Pileus white to whitish before spores mature. 2
1. Pileus honey-tan to various shades of brown at first. 3
2. Spores 6-7 X 3-3.5 iL. 103. P. pseudolactea.
2. Spores 7.5-9 X 4.5-5.5 X 5-6.3 jL. 104. P. fraxinophila.
3. Cells of pilear cuticle cinnamon to dark cinnamon when first mounted in KOH
(the pigment in the wall); habitat on or near wood of conifers. 4
3. Cells of pilear cuticle hyaline to ochraceous in KOH. 6
4. Spores 7-9 X 3.7-4.5 gu; stipe 1-1.5 cm thick; lamellae dark rusty brown when
young. 105. P. tsugae.
4. Spores smaller than in above choice and stipe thinner. 6
5. Spores 6-7.5 X 3-3.5 X 3.6-4.5 u; hyphae of subcuticular region of pileus hyaline
as revived in KOH. 107. P. sequoiae.
5. Spores 6-8 X 4-4.5 X 4.5-5.5 Iu; hyphae of the subcuticular region of the pileus
cinnamon as revived in KOH. 106. P. subalpina.