Hymenogaster and related genera.pdf - MykoWeb

630 ANNALS OF THE MISSOURI BOTANICAL GARDEN
[VOL. 21
conical; basidia -1-4-spored; spores colored, usually some shade
of brown, ochre, or almost black at maturity, ovoid, obovoid,
ellipsoid, citriform, fusiform, or lanceolate, with or without
apiculus, with or without persistent pedicel, surface smooth
to verrucose, rugose, alveolate, or reticulate, with or without
a more or less wrinkled utricle.
The peridium and tramal tissues of the gleba are little dif-
ferentiated in- the young stages. In some species they never
undergo further differentiation, while in others the outer
hyphae become larger and form a coarse stupose outer layer
which gradually merges into the gleba. The cavities develop
schizogenetically in the upper portion of the fructification,
leaving a large more or less hemispherical to conical sterile base
which persists for a long time, occasionally to maturity. As the
cavities expand above, the lower ones next the sterile base are
stretched longitudinally so that they appear to radiate from
the sterile base. The septa are very broad at first and grad-
ually shrink until they are very thin, often fragile, occasionally
scissile. The subhymenium is often pseudoparenchymatous,
the basidia are usually cylindrical and so evanescent that they
are rarely observable in mature fructifications. On drying, the
tissues throughout the fructification collapse, and thus meas-
urements based on dry material are many times less than those
based on fresh specimens or on those preserved in alcohol.
When a fructification has been preserved in alcohol for a time
and then allowed to dry out, the tissues are still more 'collapsed
and it is almost impossible to distinguish structures. Since
most of the material available in this work has been dried,
unless otherwise noted the measurements and the structures
observable in the dry material have been given in our descrip-
tions and keys. One who intends to prepare herbarium ma-
terial of this genus should make careful field notes of color,
odor, and size, and preserve most of the material in alcohol or
alcohol to which 10 per cent glycerol has been added, drying
one fructification in order to compare with dry material to be
found in other herbaria. Exceptionally fine material received
from Prof. James McMurphy, Stanford University, was pre-