North American species of Mycena.

GLUTINIPES: FULIGINELLAE

431

Observations.-To judge from my own field experience, this is one
of the most common Mycenae in North America. A two-spored form
also occurs but is apparently very rare. Its spores measure 10-12
X 4-5 (6) pi. For several years I have been interested in the sequence
with which certain Mycenae fruited in a local conifer plantation.
Both M. vulgaris and M. clavicularis are very abundant, but their
fruiting periods rarely overlap. The latter regularly fruits under
white pine late in August or early in September if the weather is
moist. No matter how wet the weather is at this time, M. vulgaris
does not fruit abundantly. During the 1940 season, in spite of what
appeared to be almost perfect weather for the growth of the fungus,
only a few depauperate carpophores of M. vulgaris appeared. When
we have a very wet cool late September or early October M. vulgaris
can be collected in almost any quantity, and M. clavicularis cannot
be found or only occasional fruiting bodies appear. The same sequence was noted when collecting in the second-growth stands of
conifers on the Olympic Peninsula of Washington during the season
of 1935. M. vulgaris did not fruit until the cool weather just before
the snow came.
Kauffman's Mt. Hood collection is apparently a fungus of the
M. filopes group. The short, stubby two-spored basidia (16-18 X
7-8 M) distinguish it sharply from M. clavicularis. The specimens
reported as M. clavicularis var. cinerea Peck by Kauffman and Smith
(1933) are referable to M. vitilis, a species neither Kauffman nor I
understood at the time. M. vitilis has an elastic stipe which sometimes feels subviscid to the touch, but does not have a differentiated
gelatinous pellicle. The type of M. clavicularis var. luteipes Kauffman has not been located, but from the description it appears to be a
form of M. epipterygia, in spite of Kauffman's comments. Bisby
reported this variety from Kenora, Ontario. The sulphur-yellow
cap with olivaceous or green shades, yellowish gills, particularly the
yellow stipe, and large spores are all too suggestive of M. epipterygia.
In dry weather the pilei of the latter may be pruinose and dry to the
touch, and the pellicle may be separable only with difficulty. In such
cases the only reliable approach to the problem of its identity is to
section the cap and make a microscopic examination. The gelatinous
pellicle in water mounts assumes its typical form and consistency
immediately.
From among Peck's collections I have notes on a specimen bearing
the name "M. clavicularis var. tenuior," which is merely a slender