Three grass smuts are recorded from tropical Australia.
Sporisorium simile destroys the inflorescence of its
host Chionachne in tropical
Western Australia. It is distinct from the inflorescence smut
Sporisorium reilianum, here recognised for the first time on Chionachne,
in
Queensland, and from the ovary smut Ustilago polytocae,
found on Chionachne in India. Recent use of binomials based on
Ustilago
holci-sorghi Rivolta for the smut named S. reilianum
is discussed and not recommended. Ustilago brunkii is recorded
from leaf sheath
lesions on Dichanthium in tropical Western Australia.
Comparison with a collection of this species from Texas, U.S.A. and with
the
type species of Jamesdicksonia from India indicates that
U. brunkii is best placed in Jamesdicksonia.
The identity of its known grass
hosts in the U.S.A., Central America and Australia, and their significance
in
its taxonomy, are discussed.