The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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States and the Great Lakes region. However, in our western mountains the area
is so large and the collectors so few that anyone with field experience will readily
realize the opportunity for future work. In the Great Lakes region the northsouth axis from Whitefish Point on Lake Superior to Ann Arbor must be considered one of the most heavily sampled areas in the world-and we still find
undescribed species in Washtenaw County.
There are reasons for the present state of affairs. First, species of Psathyrella
are like those of Cortinarius to the extent that a few common ones fruit almost
every year, but it is only in the occasional year, one in ten perhaps, that the
genus fruits heavily both as to number of species and number of basidiocarps.
Although this is now a well known pattern for a number of major groups of
fleshy fungi, it still operates as a major factor as far as plotting the distribution
of agarics over the landmasses of the earth is concerned.
A psychological factor, however, may have strongly influenced our failure to
accumulate information on the phytogeography of Psathyrellae. It has heretofore
been generally regarded as a rather insignificant genus. Hence few collectors
(including myself during my early years) have given it critical attention. Also,
the fact that the species of the genus as now defined were previously scattered
in so many different genera, did not help matters. Add to all this the fact that
the basidiocarps of most Psathyrellae are small and ephemeral, and that some
characters such as those involving the development of the veil and the color of
the pileus were either readily obliterated by poor collecting technique or are
characters which change so rapidly that it is difficult to preserve the features
until a critical study could be made, and make the reason for our slow progress
apparent. As in Rhizopogon (Smith and Zeller, 1966) I must again insist that
the present work is an introduction to the Psathyrella flora of North America,
reviewers please take note. My reason for being so emphatic in regard to these
considerations is that in a preliminary way, on a recent visit to the Royal
Botanic Garden at Edinburgh, Scotland, I had the pleasure, when working with
Peter Orton, the British specialist, of comparing notes and descriptions of
Psathyrella from the British Isles with those from North America. It became
evident at once that, while many species were quite similar in a comparison of
British and American counterparts-they were more often than not distinguished
by one or two characters now considered important. The number of species we
clearly established as occurring on both regions was a distinct minority. Orton's
unpublished data are the most critical I have seen to date for European species,
and the number he has found is certainly greater (far greater) than in any
account for Europe yet published. I had expected, frankly, that a critical comparison of the two floras would have revealed many more species common to
both areas. When the Psathyrella flora of Canada can be critically compared with
that of the British Isles, the number of species common to both should be
increased sharply.
But with the situation as pointed out for the British Isles in mind, it should
be obvious to all how much remains to be done over the world as a whole.
If it seems to some of my readers that I am belaboring the obvious, allow me to
point out that from the time I took up the study of fleshy fungi in 1928 to the
present, biologists in general, and taxonomists in other groups of fungi in particular, did and still do take the attitude that further investigations of fleshy fungi
are not badly needed because the work on the order is largely completed. This
point is most likely to come up when financial support for biology is being
considered. Yet the fleshy fungi today, with all the modern monographs included,