North American species of Lactarius / L. R. Hesler, Alexander H. Smith.

vi

Preface

eliminate L. torminosus on the basis that the fungus Gray described
can hardly be L. torminosus of Fries' work. Gray, under a subheading
which reads "cap yellowish," described L. torminosus as "pale ochryyellow" (p. 623, 1821). L. torminosus of Fries has a pink to vinaceous
tone to the pileus. Our choice (1960a) of L. deliciosus represents a
species included by Gray in the same sense essentially as the concept
of Fries (1821). L. deliciosus is also preferable because it is, in the
broad sense, well known and thus serves very well as a representative
of the genus. This is a common sense consideration, not a legal one,
but in our estimation should carry some weight when the basic legal
considerations have been met. L. insulsus, L. rufus, L. zenkeri, L. azonites, and L. piperatus have each already been indicated as types for
segregated genera. Even though we do not recognize any of these
segregates as genera, we think each should have a different type species
than the one assigned to Lactarius.
Aside from the selection of a type species, the history of the
genus is routine. Burlingham (1910b) used the name Lactaria (feminine
gender) attributing the name to Persoon. Since this time, S. F. Gray's
work has been legislated as post-Friesian so his spelling of the name
is accepted. Over the years there has been exceptional agreement by
mycologists on the scope of the genus; most treatments have merely
added more species and/or attempted to arrange them in a more natural order.
For North America, Peck, from 1872 to about 1915, made many
contributions to our knowledge of North American Lactarii. He was
followed by Burlingham (1907a & b, 1908, 1910b, and later publications).
Coker (1918) treated the species occurring in North Carolina. Murrill
(1938-48), after retiring to Florida, made a number of contributions
to our knowledge of the species of that state. Kauffman (1918)
treated the Michigan species. Burlingham's (1910b) article was the
first oriented toward the flora of North America as a whole. Hesler
& Smith (1960a & b) and Smith & Hesler (1962) published treatments
of certain sections of the genus for North America. In addition to the
major contributions mentioned above, numerous papers dealing with
individual species, those collected on expeditions, and lists connected
with local flora studies appeared.
In the present work we have strived to make major contributions
in two areas of study: We have made a concerted effort to redescribe
those species published during the past century on the basis of greater
detail as to microscopic characters and greater exactness in the gross
features. In other words, spore characters and anatomical characters
of the basidiocarp have been emphasized. It is only through such an
approach that variation within a species can be clearly indicated.