Ustilago sparsa Underw.

Description

Sori in some ovaries of an inflorescence, ovoid with an acute tip, 1.5–3.0 mm long, 1–2 mm wide, partly hidden by the floral envelopes, at first covered by a greyish brown membrane (pericarp) that ruptures irregularly exposing the dark brown semi-agglutinated to powdery mass of spores. Columella and sterile cells absent.

Spores globose, subglobose, ovoid or ellipsoidal, 7.0–9.5 (–10.5) × (5.5–) 6.0–8.5 µm, yellowish brown; wall uniformly c. 0.5 µm thick, sparingly and minutely but distinctly echinulate; spore profile smooth, wavy to finely and sparsely serrulate.

Hosts
   
Host family: Poaceae
   
Host species: Dactyloctenium aegyptium (L.) Willd.
Dactyloctenium radulans (R.Br.) P.Beauv.

Distribution

States & Territories: QLD, WA