As one of the endangered breed of mycologists to have
maintained an interest in oomycetes, I am compelled to defend
the rationale in continuing to refer to these micro-organisms
as fungi. This paper is stimulated by recent communications in
which my mycological colleagues have, with apparent relish,
pointed to what they perceive as inaccurate references to
oomycetes as fungi. David Moore (1997) provides a prime
example in his review of The Growing Fungus edited by
N. A. R. Gow & G. M. Gadd (1995). Moore criticizes the
editors for allowing so many pages of their book to be
devoted to these micro-organisms, when ‘…Neurospora
is
probably more closely related to a cow's nose than it is to
Saprolegnia’. While a phylogenetic chasm separates the
oomycetes from other fungi, I shall argue that it is impractical
to restrict the usage of the term fungus to those micro-organisms that
qualify as members of the Phylum Fungi
(Alexopoulos, Mims & Blackwell, 1996, provide a contemporary overview
of fungal systematics). This argument
should have been settled by a series of clear-sighted articles
published after molecular genetic analyses confirmed the
polyphyletic nature of the fungi (Christensen, 1990; Bruns,
White & Taylor, 1991; Hawksworth, 1991; Barr, 1992). For
example, Donald Barr (1992) suggested that oomycetes are
fungi in the colloquial sense of the term and that it is the
colloquial sense of the term that will continue to be most
meaningful to mycologists. But since the message of these
articles was apparently missed by many mycologists, I hope
that this note will clarify a practical definition of the fungi that
includes the oomycetes but which does not conflict with a
natural classification of the Phylum Fungi that excludes them.