North American species of Mycena.

MYCENELLA: NODULOSAE

443

SECTION NODULOSAE
227. MYCENA MARGARITISPORA Lange
Dansk Bot. Arkiv, (5): 37. 1914
Illustrations:
Text fig. 54, nos. 1-2 (p. 444).
Lange, Flora Agar: Dan., 2, pl. 58 D, D'.
Smith, Am. Journ. Bot., 22, pl. 3, fig. 2.
Pileus 4-10 (15) mm. broad, obtusely conic, becoming campanulate or umbonate and the margin recurved, surface appearing dry
and densely pruinose at first, becoming glabrous and somewhat
polished while still moist, fading and becoming somewhat glaucous,
deep "fuscous" on the disc or a deep glaucous gray at first, margin
pallid, fading through "army brown" to yellowish gray along the
margin, translucent-striate when moist, slightly sulcate in age, margin
regular; flesh thin, pallid, tough, odor and taste not distinctive;
lamellae adnate, usually seceding in age, rather narrow, subdistant
to moderately close, white or stained yellowish in age, pruinose under
a lens, edges even but pruinose; stipe 2-5 cm. long, 0.5-1 mm. thick,
straight or flexuous, often decumbent, cartilaginous and pliant, equal,
base strigose, covered with a dense coating of long cystidium-like
hairs, giving it a velvety appearance, deep fuscous over all or the
apex paler, often stained yellowish in age.
Spores (5) 6-8 i, globose to subglobose, verrucose, nonamyloid,
basidia two-spored; pleurocystidia and cheilocystidia 40-70 X 8-15 i,
abundant, ventricose with long necks, simple or the apices more or
less branched into three or many simple or compound branchlets,
when fresh more or less covered with a granulose substance; gill trama
homogeneous, pale yellow in iodine; pileus trama homogeneous, pellicle well formed, its cells covered with numerous short rodlike projections, pilocystidia numerous, usually smooth, 40-85 X 9-12 J, hyaline, fusoid-ventricose, tramal body filamentous and yellowish in
iodine; caulocystidia 36-90 X 7-10 l, straight or flexuous, the apices
usually contorted, branched, or incrusted.
Habit, habitat, and distribution.-Single or in groups of two or
three, on old wood, chip dirt, and debris, in the summer and fall.
Locally it is most often encountered on the black humus near stumps
in elm-maple swamps after the humus has been dried out and then
remoistened by heavy rain. The species is known from Tennessee,