North American species of Mycena.

284 NORTH AMERICAN SPECIES OF MYCENA

basidia four-spored; pleurocystidia scattered, 35-44 X 12-22 u,
capitate, with an obese or a slender pedicel, the head covered with
short rodlike projections; cheilocystidia forming a sterile band,
hyaline, similar in size and shape to pleurocystidia; gill trama homogeneous and vinaceous red in iodine; pileus trama with a well-differentiated pellicle and hypoderm, the remainder floccose but hyphae quite
enlarged, in iodine turning vinaceous red in all parts except the
pellicle.
Habit, habitat, and distribution.-Gregarious on conifer needles
and humus, also on mossy areas in hardwood forests, abundant in
some localities but generally rare in North America. It is known
from Alabama, North Carolina, Tennessee, New York, Ohio, Michigan, Washington, and Oregon. It fruits during both the summer
and fall months.
Material studied.-Smith, 32-530, 33-854, 33-915, 2742, 3276,
3473, 3499, 3517, 3563, 3614, 7823, 16233, 16436, 16951. Atkinson,
six packets, New York. Burke, 1942, Alabama. Hesler, 12944,
11792, 14205. Kauffman, two collections. Slipp, UIFP: 2673.
Observations.-This is a slender gray to somewhat avellaneous
species which develops a long stipe even when growing in open places.
The lack of any distinctive odor readily separates it from M. iodiolens.
In addition, the margin of the pileus in M. iodiolens usually consists
of a very narrow sterile membrane, that is, the gills do not extend
to the edge of the cap. M. atroalboides has a short stipe when growing in similar habitats, and frequently develops reddish stains in age.
These are all secondary characters, it is true, and in certain groups of
species would not be given much emphasis. However, ten years of
field experience have convinced me that all three species are quite
readily recognizable in North America, and that intergradations are
not particularly numerous.
Mycena albogrisea Peck appears to be a small form of M. filopes.
I have examined the type and found the spores to measure 8-11 X
4-5,. A few 11-13 X 6-7, were also observed. The remaining
microscopic characters are as given in the description. No bispored
basidia were seen. There is a resemblance between the type specimens of M. albogrisea and large dried carpophores of M. capillaris,
but I have never observed the latter either with a stipe 1 mm. thick
or occurring on carpets of conifer needles. Some may prefer Peck's
name for this species as a convenient way of avoiding the confusion