The North American species of Psathyrella.

6

MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

[ VOL. 24

indestructible, and the main purpose of wrapping is to insure that the spores of
the various collections are kept isolated from each other. Great care should be
taken to keep the specimens of fleshy fungi from becoming overheated in transporting them back to the laboratory. If allowed to overheat the color changes of
the context on cutting may be (usually are) arrested or are unreliable, or the
whole basidiocarp may become so wet that it will not be fit for study because the
colors have been lost and tissues collapsed. Such poorly preserved specimens are
all too numerous in herbaria.
As soon as one has returned to the laboratory, place the collections in a
relatively cool place and spread them out so that the individual packages can
"breathe"; if piled in a heap they will sweat and lose important characters before
they can be properly studied. As soon as possible after returning from collecting,
photograph such collections as are deemed worthy of a photo from your standpoint, and then for each of these collections write a complete description patterned
after the descriptions (of the macroscopic characters) as found in the following
text. The type of photograph taken will depend on the use planned for it. One
may want color transparencies for lecture purposes, or black-and-white prints for
possible publication later on, or the picture may simply be used to refresh the
collector's memory at a later date. I use 4 x 6 inch cards for my "field" descriptions, and a 4 x 5 inch negative size for black-and-white pictures. Small specimens can be taken natural size and larger ones reduced to half size or less on the
negative.
When these operations are complete, write a "field label" for the collection. On
it should appear the collector's name and the number of the collection, the latter
in the upper lefthand corner. Below it record the name of the fungus to order,
family genus or species depending on how well you can identify it at the moment.
Also record the nature of the substrate on which the specimens occurred as
accurately as you can identify it, and the date of the collection, the county and
location in the latter if that is meaningful. Add the data on the field label in the
upper righthand corner of the card on which you wrote the description. The name
of the fungus or the group to which it belongs is entered in the upper lefthand
corner on the card containing the description.
When all these operations have been completed place the specimen on a drier.
If one is drying numerous collections a drier such as illustrated by Smith (1947)
is desirable, only use hot plates as a source of heat rather than a gasoline stove
since the former give a drier heat and are less of a fire hazard. NEVER place the
label or any paper under the specimens. Fold the label so that the collection
number and generic name, if you have it, are readily visible, and place it either
to the right or left of the specimen-but be sure to always do it the same way so
that the proper label is always placed with the proper specimen when the latter
is removed from the drier. If the basidiocarps are very small, the silica gel method
described by Hoseney (1963) is recommended: Fill with activated silica gel of
moderately large mesh (medium sized particles, not the powder) to about half
full a small refrigerator dish which can be tightly closed. Place the specimen with
its label on the silica gel, but do not bury the specimen. Close the dish and allow
to stand for 24 hours. If the specimen has become brittle by that time (or sooner),
it is dry. Carefully rewrap it in waxed paper as you did when you collected it but
include the label, and store in a carton for eventual transfer to your home
laboratory-if you are at some field location, or for later study when the rush
of fresh material is over, such as during the winter months. If the silica gel
changes from blue to white and the specimen is not yet dry, transfer it to a fresh