Ustilago chloridis Vánky, C. Vánky & R.G. Shivas

Description

Sori in some ovaries of an inflorescence, lemon-shaped to obovoid, 2–3 mm long, 1.0–1.5 mm wide, visible between the floral envelopes, covered by an initially green, later yellowish brown membrane (pericarp) that ruptures irregularly exposing the blackish brown powdery mass of spores and a short thick columella.

Spores subglobose to ellipsoidal, slightly flattened (8–11 µm wide), (10–) 11.0–13.5 (–15) × 9.5–13.0 µm, medium reddish brown; wall unevenly thick, on the flattened sides thin, c. 0.5 µm, elsewhere c. 1 µm, sparsely low-verrucose; spore profile smooth or very finely serrulate, especially on the flattened sides.

Sterile cells in irregular groups; individual cells globose, 7–10 µm, hyaline, smooth.

Hosts
   
Host family: Poaceae
   
Host species: Chloris divaricata R.Br.
Chloris lobata Lazarides
Chloris pumilio R.Br.
Chloris truncata R.Br.

Distribution

States & Territories: NSW, NT, QLD

Comments

The presence of a columella and sterile cells indicates that this smut might be better placed in Sporisorium. However, the circumscriptions of Ustilago, Sporisorium and Macalpinomyces are not clear owing to the occurrence of intermediate forms.