The North American Species of Crepidotus

45. Crepidotus constans sp. nov.

Illustration: Fig. 101.

Pileus 3-15 mm latus, sesilis, ungulatus demum convexus vel paene planus aut flabelliformis, favus velpallido-melleus, pubescens, striatus, incurvatus. Lamellae albae demum subflavae denique obscuro-brunnaceae, latae vel medio-latae, subdistantes vel paene confertae. Sporae 4-5.5 µ, globosae, nonnullae ovoideae, punctatae. Basidia 20 -28 x 5-7 µ, tetraspora. Pleurocystidia desunt; cheilocystidia 33-71 x (3) 5-11 µ. Cuticula ex hyphis repentibus composita, hyphas erectas et pileocystidia gerens, 37 -120 x (2) 5-9 µ. Fibulae adsunt. Specimen typicum in Herb. Univ. Mich.; lectum prope Harbor Springs Hills, Mich., July 25, 1961, A. H. Smith 63670.

Pileus 3-15 mm broad, sessile, ungulate to convex or nearly plane, or flabelliform, yellow or pale honey yellow, pubescent, base byssoid, the fibrils whitish or buff, margin incurved, striate when fresh. Context thin, white to buff; taste none.

Lamellae whitish to pale yellowish, then dull brownish, broad or medium broad, subdistant or nearly close, edges fimbriate or denticulate.

Spores 4-5.5 µ in diameter, globose, some ovoid and then distinctly pointed one end, punctate. Basidia 20-28 x 5-7 µ, 4-spored. Pleurocystidia none; cheilocystidia 33-71 x (3) 5-11 µ, cylindric, often capitate, at times irregular. Gill trama subparallel, hyphae 4-14 µ broad. Pileus trama interwoven. Cuticle of repent hyphae, bearing erect, colorless hyphae, the terminal elements as pileocystidia , 37-120 x (2) 5-9 µ; those on the margin similar to the cheilocystidia. Clamp connections present.

Habit, Habitat, and Distribution: On hardwood logs, Michigan, July-August.

Material Studied: MICHIGAN: Smith 41547, 61485, 63513, 63571, 63670 (type, from Harbor Springs Hills, July 25, 1961).

Observations: The yellowish color of the pileus is unchanged, from youth to maturity; otherwise, the species is similar to C. obfuscens.