Introduction to Fungi, Third Edition

518 HOMOBASIDIOMYCETES
There are three main hyphal types. (1)
Generative hyphae are thin-walled near the
margin of a basidiocarp but often thickerwalled
behind, with or without clamp connections,
usually with cytoplasmic contents. This
kind of hypha is universally present in all
basidiocarps at some stage of development.
The generative hyphae produce basidia and
other types of cell making up the hymenium,
and they also give rise to the other kinds
of hyphae from which the basidiocarp is
constructed (Fig. 19.3a). (2) Skeletal hyphae are
unbranched or sparsely branched, thick-walled
hyphae with a narrow lumen. They arise as
lateral branches of generative hyphae and form
a rigid framework (Fig. 19.3c). (3) Binding
hyphae (sometimes termed ligative hyphae) are
much-branched, narrow, thick-walled hyphae of
limited growth. These hyphae weave themselves
between the other hyphae and bind them
together (Fig. 19.3b).
Several other kinds of hypha have been
described, some as intermediates between the
above three principal systems. Sarco-hyphae
are composed of long, greatly inflated, mostly
unbranched cells 500 3000 10 30 mm
with relatively narrow septa. They can be interpreted
as skeletal, inflated generative hyphae.
In Amauroderma rugosum (Ganodermataceae)
skeleto-ligative hyphae resembling skeletal
hyphae have thick-walled contorted branches
and function in the same way as binding
hyphae. Arboriform skeletal hyphae with terminal
thick-walled branches are present in the
basidiocarps of Ganoderma (see Figs. 19.23b,c).
Gloeoplerous hyphae have dense oily contents
(Fig. 19.27). The diverse hyphal types may be
present in basidiocarps in different
Fig19.3 Hyphal analysis of material dissected
from the fruit body of a trimitic polypore,
Trametes versicolor. (a) Generative hyphae
characterized by thin walls, dense cytoplasmic
contents and clamp connections. (b) Binding
hyphae, branched, contorted and thick-walled.
The arrow shows the origin from a generative
hypha. (c) A skeletal hypha, unbranched and
thick-walled, originating from a generative
hypha (arrow).