Introduction to Fungi, Third Edition

574 HOMOBASIDIOMYCETES
P. pomaceus on plum trees (Prunus), and P. robustus
on oak (Quercus).
Phellinus pomaceus has been extensively
examined for the mechanism by which it
produces the greenhouse gas chloromethane.
This activity is indirectly associated with its
lignin degradation system (see p. 527).
19.10 Cantharelloid clade
This is a further group of Homobasidiomycetes
with a wide range of morphologically different
basidiocarps. Species likely to be encountered
during forays belong to the Cantharellaceae,
Hydnaceae and Clavulinaceae. Pine et al. (1999)
have provided evidence of the relationship
between these groups. Hibbett and Thorn (2001)
have suggested that Tulasnella might be included
in this group, but since members of this genus
produce heterobasidia, we regard them as
belonging to the Heterobasidiomycetes (see
Fig. 21.1b).
19.10.1 Cantharellaceae
The genera Cantharellus and Craterellus belong to
the most sought-after edible species. Cantharellus
and related species are known as the chanterelles,
with C. cibarius being the most readily
recognized (Plate 10g). Another abundant,
although less well-known, edible species is
C. tubaeformis (Fig. 19.30a). The fruit bodies of
most Cantharellus spp. appear in vibrant yellow or
red colours due to carotenoid pigments, including
canthaxanthin in the case of C. cinnabarinus.
The fruit bodies are funnel-shaped, and the
hymenium consists of shallow branching ridges
which are strongly decurrent. The number of
sterigmata and basidiospores on the basidium
of C. cibarius seems to vary in the range of 4 7.
In Craterellus cornucopioides, the horn of plenty
or death’s trumpet, the hymenium is smooth,
and the fruit bodies are trumpet-shaped with a
hollow stipe.
Members of this group are ectomycorrhizal
with coniferous (Picea, Pinus) and broad-leaved
(Fagus) trees, and it has been possible to
grow C. cibarius on agar-based media and to
Fig19.30 Basidiocarps in the cantharelloid clade.
(a) Cantharellus tubaeformis.(b)Hydnumrufescens, the hedgehog
fungus. (c) Clavulina cristata.
generate mycorrhizal associations under laboratory
conditions (Danell, 1994). There is hope
that a method may ultimately be developed
towards commercial production of fruit