Sporisorium incompletum R.G. Shivas & Vánky

Description

Sori in some spikelets of an inflorescence, showing between the spreading glumes, lemon-shaped or ellipsoidal with an acute tip, 2–3 mm long, 1.0–1.5 mm wide, at first covered by a thin greyish peridium that ruptures irregularly exposing the dark brown powdery mass of spores surrounding a short stout columella.

Spores when mature solitary, ellipsoidal, ovoid or rounded-irregular, more rarely subglobose, elongate or tear-shaped with a subacute tip, slightly flattened, 6.5–8.0 µm wide, in surface view 9–13 (–15) × 8.0–11.5 µm, pale yellowish brown; wall uniformly c. 0.5 µm thick, moderately densely and finely verrucose-echinulate; spore profile ±smooth to finely serrulate.

Sterile cells absent.

Hosts
   
Host family: Poaceae
   
Host species: Cynodon incompletus Nees

Distribution

States & Territories: NSW

Comments

Cynodon incompletus is native to South Africa, but it has become established in Australia and Argentina. Two other smut species, Ustilago cynodontis and Sporisorium normanense, have been found on Cynodon in Australia. A key to the eight species of smut fungi that occur on Cynodon worldwide was provided by Shivas & Vánky (2007).