Ustilago syntherismae (Schwein.) Peck

Synonyms

Caeoma (Uredo) syntherismae Schwein.
Sorosporium syntherismae (Schwein.) Farlow
Sphacelotheca digitariae-pedicellaris J.N. Mishra
Ustilago belgiana Zundel
Ustilago destruens var. digitariae Sacc.
Ustilago digitariicola Speg.
Ustilago rabenhorstiana
J.G. Kühn

Description

Sori in the inflorescence replacing the spikelets with a blackish brown semi-agglutinated to dusty spore mass, at first hidden by enveloping leaf sheaths, later visible, 3–5 cm long. Finally, only the destroyed rachises of racemes remain, sometimes with a few distal aborted spikelets.

Spores globose, ovoid to slightly irregularly elongate, 10–15 × 9–12 (–13) µm, light to dark olivaceous brown, minutely and moderately densely echinulate; spore profile finely to distinctly serrulate.

Hosts
   
Host family: Poaceae
   
Host species: Digitaria ciliaris (Retz.) Koeler
Digitaria horizontalis Willd.
Digitaria sanguinalis (L.) Scop.

Distribution

States & Territories: NSW

Comments

Ustilago syntherismae is one of five species of smut fungi which infect Digitaria in Australia. Although it has been considered the most common smut on Digitaria (Vánky, 1999c),
U. syntherismae and the other species have rarely been collected in Australia.