North American species of Crepidotus, by L.R. Hesler and Alexander H. Smith.

108

North American Species of Crepidotus

92. Crepidotus variabilis (Fr.) Kummer Der Fiihrer in die Pilzk.,
p. 74. 1871. var. variabilis.
Agaricus variabilis Fr., Syst. Myc. 1: 275. 1821.
Agaricus (Crepidotus) cheimonophyllus B. & Br. apud Berk. Outlines, p. 164.
1860.
Claudopus variabilis (Fr.) Gill., Champ. Fr., p. 426. 1876.
Dochmiopus variabilis (Fr.) Pat., Hymen. Europe, p. 113. 1887.
Crepidotus cheimonophyllus (B. & Br.) Sacc., sensu Sydow, Syll. Fung. 5: 882.
1887.
Illustration: Fig. 164.
Pileus 4-20 mm broad, resupinate to reflexed, attached laterally or
dorsally, flabelliform, dimidiate or reniform, white, villose or tomentose, dry.
Context moderately thin.
Lamellae radiating from a lateral point, white then ocher-flesh to
pinkish-cinnamon, close or subdistant, medium broad, edges fimbriate.
Stipe none, or present when young and then very short, eccentric, and
temporary.
Spores 4.5-6 X 2.5-3.5(4) /j, oblong-ellipsoid, at times subovoid,
punctate, pale brownish. Basidia 20-28 X 5-6 /, 2-4-spored. Pleurocystidia
none; cheilocystidia (18)20-50 X 5-16 u, clavate, ventricose, at times capitate, occasionally forked or branched, more rarely subcuneate. Gill trama
interwoven, hyphae 3-7 u broad. Pileus trama interwoven. Cuticle of repent hyphae, bearing a turf of hyphae 3-4 /u broad, colorless, densely
tangled, those on the margin at times flexuous. Clamp connections present.
HABIT, HABITAT, AND DISTRIBUTION: On hardwood, Michigan; England
and Netherlands,July-October.
MATERIAL STUDIED: MICHIGAN: Smith 66824; ENGLAND: Smith
63231 (MICH); Wakefield 8-10-36 (K); 4-11-45 (K); Dennis 30-9-51
(K); Reid (TENN 24024); NETHERLANDS: Bas (TENN 26105).
OBSERVATIONS: The collections we have studied seem to exhibit some
variations in spore-width, and in the form of the cheilocystidia. Those which
have spores up to 2.5-4 p broad, and regularly shaped cheilocystidia, we
interpret as C. variabilis var. variabilis; those with relatively broader spores
(4-5 4), we refer to variabilis var. subsphaerosporus; and, finally, those with
typical spores (2.5-4 I/ broad), but with filamentous, often flexuous and
branched cheilocystidia, we refer to variabilis var. trichocystis.
93. Crepidotus variabilis var. trichocystis var. nov.
Illustration: Fig. 165.
Pileus 4-12 mm latus, sessilis, ungulatus, albus, fibrillosus. Lamellae albae
demum roseae, denique brunnaceae, confertae velpaene subdistantes, latae. Sporae 4.5-6
X 2.8-4 I, ellipsoideae, punctatae. Basidia 18-25 X 5-6 pj, di- et tetraspora.
Pleurocystidia desunt; cheilocystidia 30-55(82) X 2-5(6) I, gracilia. Cuticula ex