Introduction to Fungi, Third Edition

314 PLECTOMYCETES
litter layer under various trees, but especially
beech with which they form ectomycorrhizal
associations. Elaphomyces muricatus is often parasitized
by Cordyceps ophioglossoides forming yellow
mycelium around the subterranean fruit bodies,
and a club-shaped perithecial stroma above
ground (Plate 4f). There are 5 British species
(Pegler et al., 1993) and about 20 species worldwide.
Elaphomyces spp., along with other truffles
and epigeous fungi, form an important part
of the winter diet of squirrels (Currah et al.,
2000). The common name, hart’s truffle, indicates
that the fruit bodies of Elaphomyces spp.
are dug up and consumed by deer.
The fruit bodies of Elaphomyces vary in size
(about 1 4 cm in diameter) and are regarded as
cleistothecia. When cut open, a two-layered rind
(peridium) can be distinguished from a central
mass containing the globose asci, traversed by
lighter sterile ‘veins’. The asci in E. granulatus
usually contain six spores and in E. muricatus two
to four. The spores are dark brown and thickwalled
when mature, and the conditions necessary
for their germination are not known. There
are no anamorphic states.
Further evidence of the remarkable plasticity
of fruit body morphology in the fungi comes in
the shape of an unusual member of the
Elaphomycetaceae from tropical South America.
In Pseudotulostoma, a subterranean initial produces
a sizeable stalk (up to 7 cm high) with
a head which looks much like the gleba of
a puffball but is, in fact, a cleistothecium.
At maturity, the peridial layers disintegrate,
leaving the ascospores to be distributed by the
wind (Miller et al., 2001).