North American species of Mycena.

30 NORTH AMERICAN SPECIES OF MYCENA
connective hyphae in the interior, but the peripheral layer is a sheath
of narrow hyphae with gelatinous walls. These have the characteristic translucent or "glassy" appearance and appear to be widely
separated. The chief source of error in ascertaining this character
from dried material is that the gelatinous layer may be torn away
in the process of sectioning. The sections should be floated on a
razor. In M. insignia the viscidity is caused, not by a layer, but by
numerous individual hyphae projecting from the stipe and possessing
gelatinous tips. They are sticky in wet weather but soon dry out
and leave the stipe perfectly dry to the touch. M. laevigata will
create some difficulty because the outer layer of hyphae on its stipe
gelatinizes only slightly, causing it to be slippery or lubricous to the
touch. In wet weather the hyphae may gelatinize enough to cause
the stipe to be covered with a thin layer of gluten. In 1929 this led
me to describe the fungus as a variety of M. vulgaris.