View A43-1112-1979-eng.pdf

EDIBLE AND POISONOUS MUSHROOMS OF CANADA
RUSSULA
Russula is similar to Lactarius in having sphaerocysts present in the tissue
of th« fruiting body and in the broadly ellipsoid to subglobose, rough-walled,
amyloid spores, but differs in the absence of a latex. The rather stiff stature and
brittle texture that characterize these two genera are difficult to describe in
words but are soon easily recognized in the field.
Russula is one of the largest and most important genera of the mushrooms.
It is also one of the most difficult genera in which to make accurate identifica-
tions of species although it has been studied intensively by many mycologists.
One reason for this is that there appear to be a great many species that are very
similar and differ only in small characters so that many misidentifications
have occurred and different authors will be found applying the same name to
different fungi. Another reason is that Russula species frequently occur only
singly and sporadically and it is difficult to study the range of variation of a
species; consequently there is considerable difference of opinion as to the
species limits in the genus.
Although Russula is usually classified among the white-spored genera,
the color of the spore deposit varies in different species from pure white to
cream, pale yellow, pale ochre or bright ochre. The exact color of the spore
deposit is very important in the identification of species of Russula and a good
deposit should be obtained from every collection. The spores, as in Lactarius,
are typically broadly ellipsoid to subglobose, strongly amyloid, and ornamented
with warts, spines, or a network of ridges, and the pattern of ornamentation is
important in critical determination of the species. The attachment of the
lamellae varies from adnexed to adnate or sHghtly decurrent and one section of
the genus is characterized by having the lamellae alternately long and short.
The pileus is often brightly colored in shades of red, yellow, purple, green,
or bluish, although there are some species with dull colors of white or brown.
They may be dry or viscid, glabrous or pruinose to tomentose, and the margin
may be more or less tuberculate-striate. The taste varies in different species
from mild to acrid, bitter, nauseous, etc., and this should be noted in fresh
specimens since it is an important character to aid in distinguishing species.
Some authors claim that all russulas are edible and that the acrid taste
disappears on cooking. However, we do not recommend eating the acrid
species and they should be tried very cautiously if at all. One species, R. vesi-
catoria Burl., described from Florida and also known on the west coast, is
reported to cause blistering of the lips and tongue when tasted. Also species
like R. foetens, which have a very unpleasant odor and taste, should certainly
be avoided.
Only a few of the commoner species are described here. The collector will
find many others that he will be unable to identify with this book.
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