North American species of Mycena.

EUMYCENA: TYPICAE

239

examining material from the type and other collections it was found
that a positive amyloid reaction was not obtained on either the spores
or any part of the tissue of the pileus or stipe. The error in the
previous observation was very likely caused by certain spores remaining hyaline in the yellowish iodine solution and, consequently,
appearing very faintly bluish in contrast to the surrounding field.
The nonamyloid reaction of the spores is unique for a Mycena
of this kind and furnishes an excellent character by which dried material can be identified. M. plumbeibrunnea Murrill (see "Excluded
Species," p. 487) has amyloid spores, but since it could be placed in
any one of several of the gray species, the name has been discarded.
110. MYCENA ABRAMSII Murrill
Mycologia, 8: 220. 1916
Prunulus Abramsii Murrill, North Am. Flora, 9: 338. 1916.
Illustrations: Plate 38; Text fig. 27, nos. 1-4 (p. 240).
Pileus 1-3 cm. broad, 1-2 (3) cm. high, nearly cylindric with an
obtuse apex when young, becoming broadly conic to conic-campanulate, broadly expanded and umbonate in age or remaining unexpanded, margin appressed against the stipe when young, often flaring
in age, surface pruinose and with a stannous sheen at first, glabrous
and soon naked, somewhat translucent-striate when moist, usually
sulcate in age, colors "Chaetura black" when young and fresh, soon
"fuscous" to "drab," very hygrophanous and soon fading to pale gray,
the margin frequently paler than the disc throughout its development; flesh very fragile in large caps, pallid grayish, odor and taste
not distinctive; lamellae ascending-adnate, subdistant to distant,
18-20 reach the stipe, narrow to moderately broad (2.5-3 mm.), equal
to subventricose; pallid gray, edges even and pallid; stipe 3-8 cm.
long, 1-3 mm. thick, equal, very fragile, watery, hollow, base whitestrigose, lower portion sometimes with scattered appressed white
fibrils, upper porton at first covered with a conspicuous bloom which
soon disappears, in age glabrous and polished, concolorous with the
pileus or merely pale gray with a whitish apex.
Spores subcylindric (10) 11-13 (15) X 4.5-5.5 (6) t, amyloid;
basidia four-spored, 26-30 X 6-7 1u; cheilocystidia and pleurocystidia
similar, rare to scattered on sides, abundant on edges of gills, varying
greatly in shape from club-shaped to vesiculose and sometimes
elongated and fusoid-ventricose with acute apices, smooth or with
a few fingerlike protuberances developing and present on the elon