North American species of Mycena.

DIAGNOSTIC CHARACTERS

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pearance. The cartilaginous forms fade more slowly and, because
the change is not so abrupt, they are usually described as "subhygrophanous.
The viscidity of the pileus is a character of major importance, and,
fortunately, one's observations can be checked by microscopic examination. In some species the hyphae of the cuticle of the pileus or
stipe, or both, gelatinize and cause these surfaces to be very slimy
or sticky. The technical terms for this condition, which are "viscid"
and "glutinous," merely express different degrees of the gelatinizing
process. If the pileus is viscid, the gelatinous pellicle can usually be
removed, at least in part, and appears as a thin, transparent skin.
In some, such as M. quinaultensis, it is too thin and too highly gelatinized to hold together and can be removed only in shreds. In
others, for instance, M. laevigata, the pellicle may be adnate (not
separable from the cap) and only subgelatinous, a condition causing
the pileus to feel lubricous or slippery instead of truly viscid. As one
might expect, weather conditions will have considerable influence on
a character like this, but one soon learns to allow for them. In dry
weather typically viscid layers may seem to be merely lubricous.
In continued rainy weather they may be completely washed away,
and the surface will then feel moist instead of sticky. This happens
not infrequently in regions such as the rainy belt along our Pacific
coast. When one is collecting under these conditions, it is necessary
to obtain young fruiting bodies which have not had the gluten washed
off the stipe or cap by continuous rain. This may seem obvious to
many readers, but it should be pointed out that species like M. clatcularis often produce hundreds of fruiting bodies, all in more or less
the same stage of development. When a collector finds such quantities of material, he is not likely to spend much time searching for
immature carpophores, and thus may, because of the sheer abundance
of carpophores, fail to collect those giving the clue to the identity of
the species. Prolonged rainy weather will cause the pellicle of some
agarics not ordinarily classed as viscid to be somewhat sticky to the
touch. Here again, however, the young rapidly developing carpophores will not be misleading.
Many species have a hoary appearance when young. This character is found on the dry, moist, and viscid species alike, and is caused
by delicate microscopic cells, which soon collapse and disappear.
Lubricous, viscid, or glutinous species, when old, usually have a
polished or varnished appearance because of the dried gluten. In