North American species of Mycena.

356 NORTH AMERICAN SPECIES OF MYCENA

SECTION OMPHALIARIAE
The species of this section are distinguished from the gray species
of the Deminutivae and the Typicae by their horizontal, broadly
adnate, or more or less decurrent gills. In a certain measure the
section also bridges the gap between the Typicae of Eumycena and
the gray species of Glutinipes. It contains more than a single phylogenetic series. The range in the microscopic characters noted for the
Typicae is also present here.
There follows a list of species which might be sought for in this
section because of the manner in which the gills are attached, but
which have been placed elsewhere in order to keep closely related
species together: M. semivestipes, M. rubrotincta, M. laevigata, M.
ochraceicinerea, M. latifolia, M. peltata, M. pusilla, and M. tenuiceps.
All these are in the Typicae. For small species on the bark of living
trees see the section Corticolae (pp. 66-76). M. insignis and M.
clavicularis of Glutinipes may be sought for here if their stipes have
dried somewhat or have been severely rain-washed.
KEY TO SPECIES
1. Cheilocystidia smooth, fusoid to filamentous or basidium-like...... 2
1. Cheilocystidia clavate, with roughened apex or apex elongated and
ventricose portion verrucose.................................. 18
2. Pleurocystidia scattered to abundant............................ 3
2. Pleurocystidia, if present rare, and usually near gill edge.......... 8
3. Spores small, broadly ellipsoid to globose (4-6 X 3-5 j)........... 4
3. Spores larger or more narrowly ellipsoid......................... 5
4. Spores subglobose, 5-6 X 4-5. (spores not amyloid?)
Omphalia clavata
4. Spores 4-5 X 3-3.5,, amyloid............... 178. M. praedecurrens
5. Spores pseudo-echinulate (with fine pores through spore wall-stain
spores and observe with oil-immersion lens); pleurocystidia subcylindric, prominent.......................... 232. M. cineraria
5. Spores smooth, pleurocystidia ventricose, at least when young...... 6
6. Pileus viscid............................ 185. M. pseudoclavicularis
6. Pileus moist, usually hygrophanous........................... 7
7. Pileus turbinate; pleurocystidia 40-55 X 7-11.... 189. M. turbinata
7. Pileus convex-depressed; pleurocystidia 25-30 X 7-12,
188. M. pseudogrisea