North American species of Mycena.

EUMYCENA: ADONIDAE

171

Habit, habitat, and distribution.-Scattered or in groups of two to
four, usually on buried remains of hickory nuts and walnuts in September, October, or November; North Carolina, Tennessee, New
York, Michigan, and Illinois.
Material studied. -Smith, 32-479, 32-519, 15501 (white form),
15515. Hesler, 5770, 6512.
Observations.-This agaric can be recognized at sight by the
curious habitat, brilliant color, and almost Hygrophorus-like appearance. It is one of the very brightly colored species, but does not
appear to be closely related to such Mycenae as M. roseipallens and
M. amabilissima. Its conspicuous cystidia, the well-differentiated
hypoderm of the pileus, and the amyloid immature spores are its
outstanding microscopic characters. As Kiihner noted, the spores
often appear to be roughened by thin plates of adhering material
which give a very strong amyloid reaction. The mature spores
which I have examined do not appear to be roughened (under oil
immersion) and do not give an amyloid reaction, but I have had only
one spore deposit from which to study this reaction.
A single fruiting body of a fungus identical with M. luteopallens
in all respects except color was found near Ann Arbor in 1940 (15501).
It was white in all parts. It grew from an old walnut husk in the
locality where M. luteopallens usually occurs. It was fertile and had
smooth spores, 7-9 X 4-5 j, and the usual cystidia and hypoderm.
There was no possibility of its being a faded carpophore. If this
form is ever found in any quantity, it will bring up an interesting
question concerning its taxonomic position and also the emphasis
that should be placed on color as a specific character. With the
information at hand it hardly appears justifiable to consider it anything more than an albino form.
76. MYCENA LEPTOPHYLLA (Pk.) Saccardo
Syll. Fung., 5: 304. 1887
Agaricus (Mycena) leptophyllus Peck, Ann. Rep. New York State Mus.,
24:63. 1872.
Prunulus leptophyllus Murrill, North Am. Flora, 9: 325. 1916.
Illustration: Text fig. 17, ho. 3 (p. 173).
"Pileus thin, campanulate or convex, subpapillate, smooth, striatulate when moist, pale reddish-yellow, the disk brighter colored;