The North American species of Psathyrella.

1972]

PSATHYRELLA

413

slightly darker in age, very fragile, glabrous or with a few loose fibrils as the
remains of the thin veil.
Spores 7.5-9x4-4.5(-5) ft, smooth, apical pore small but distinct and apex
scarcely truncate, shape in face view elliptic to ovate, in profile obscurely
inequilateral, color in KOH dull bister becoming fuscous then chocolate-brown,
in Melzer's reddish tawny, wall about 0.4 A thick.
Basidia 4-spored, 15-20 x 7-10 A, short and broadly clavate, hyaline in KOH.
Pleurocystidia scattered, 32-46 x 8-12 jx, fusoid-ventricose with acute to subacute
apex, neck often elongated to a flexuous obtuse proliferation, wall thin, smooth
and hyaline, cell content not distinctive. Cheilocystidia either similar to pleurocystidia or clavate and 18-32 x 7-12 pu.
Gill trama regular, of more or less interwoven hyphae with enlarged cells having cocoa-colored walls as revived in KOH, walls smooth to minutely incrusted;
subhymenium cellular, the cells with pale cinnamon to hyaline walls. Pileus trama
of broad interwoven hyphae yellowish brown to cinnamon in KOH and with walls
minutely incrusted, the cross walls often dark cinnamon; cuticle of vesiculose cells
about 2 deep and with smooth walls yellowish to cinnamon as revived in KOH.
Clamps present.
Habit, habitat and distribution. Solitary to scattered or gregarious in small
groups, on sandy waste land near scrub oak, after heavy rains late in the fall,
Oakland and Livingston Counties in Michigan. The type was collected at the edge
of a pine plantation on the former property of the Seymour Club (now the Proud
Lake Recreation Area) in Oakland County.
Observations. The species is easily overlooked because of its small size and the
habitat (which is unusual for a Psathyrella). None of the specimens observed
showed any tendency toward reddish tints when fresh or faded. The broadly
adnate gills remind one of the gill attachment in species of Psilocybe (Deconica),
as does the dull brown stipe at maturity or in age. Good collections were made
near Oak Grove, Michigan in October 1971 as the present work was being set up
in type (Smith 81044, 81045, 81046). A description of this material is given in
Appendix I.
390. Psathyrella fulvoumbrina A. H. Smith, sp. nov.
Pileus 1-3 cm latus, late convexus, glaber vel ad marginem tenuiter floccosus,
sordide cinnamomeus; lamellae confertae, latae, brunneolae demum purpureobrunneae; stipes 1.5-3(-4) cm longus, 3-5 mm crassus, pallidus demum brunneolus, sparse fibrillosus, glabrescens; sporae 7-8.5x4.5-5 u; pleurocystidia 32 -47x9-14 p; versiformia; fibulae adsunt. Typus. Trueblood 3167 (MICH);
Boulder Creek, Owyhee County, Idaho.
Pileus 1-3 cm broad, obtuse to convex and with an incurved margin when
young, expanding to broadly convex or nearly plane and some with a slight umbo,
glabrous except for patches of the fibrillose thin veil along the margin at first
(not appendiculate), color dingy cinnamon-brown but when dried dark grayish
brown (umbrinous), striatulate when moist. Context concolorous with surface
when moist, paler brownish faded.
Lamellae close, broad, adnate, dull tan becoming dark purplish brown when
mature and dark vinaceous-brown as dried, edges even and concolorous with faces
in age, pallid at first.
Stipe short, 1.5-3(-4) cm long, 3-5 mm wide, straight to flexuous, white at