( 1984 ), who suggested that the basidial “com-
partments” themselves may actually be meiotic
products (endospores) that in most species
form a germtube (the so-called epibasidium)
to produce a secondary spore (basidiospore in
common terminology). Longitudinal, trans-
verse, or oblique septation of the basidium
then may simply result from a varying arrange-
ment of the primary spores (endospores)
within the basidium.
Teliospores, i.e., one-celled conidia that
give rise to basidia after a resting period, are
only known from species of Cystofilobasidiales.
These structures provide an eloquent example
of convergent evolution as they are present in
various distantly related groups of basidiomy-
cetes, such as the rust and the smut fungi.
Many presumably mycoparasitic species of
Tremellomycetes feature a characteristic tre-
melloid haustorial type in their filamentous
stages (e.g., Chen 1998 ; Oberwinkler and Ban-
doni 1981 ; Zugmaier et al. 1994 ) (Fig.12.2c, f,
g).Tremelloid haustoriaarise from clamp con-
nections and consist of single cells that are
globular or short clavate at the base and extend
into one or more narrow filaments (Fig.12.4).10 μm10 μm10 μm
20 μm20 μm 10 μm20 μma
d g
h
f
c
b
e
Fig. 12.2Basidial characters in Tremellomycetes. (a)
Cuniculitrema polymorpha(Kirschner et al. 2001 ). (b)
Papiliotrema bandonii(Sampaio et al. 2002 ). (c)Tetra-
goniomyces uliginosus (Oberwinkler and Bandoni
1981 ). (d)Trimorphomyces papilionaceus(Oberwinkler
and Bandoni 1983 ). (e)Bulleribasidium oberjochense
(Sampaio et al. 2002 ). (f)Rhynchogastrema coronatum
(Metzler et al. 1989 ). (g)Phragmoxenidium mycophi-
lum(Oberwinkler et al. 1990 ). (h)Sirobasidium mag-
num(Chen 1998 ). Drawings reprinted with permissionTremellomycetes and Related Groups 335