Tilletia geeringii Y.M. Li & R.G. Shivas

Description

Sori in ovaries of some spikelets, 3–4.5 × 1 mm, ellipsoidal to fusiform, hidden by the lemma and glumes, covered by the peridium which ruptures longitudinally to expose the semi–agglutinated to powdery mass of spores and sterile cells.

Spores subglobose, ellipsoidal to slightly irregular, (19–)21–25(–26) × (17–)18–22 µm, reddish brown, verrucose, wall 3–5 µm thick including the blunt to subacute warts 1.5–3 µm high, in surface view the warts appear as subpolyangular regions, 7–12 per spore diam, 35–60 on the spore circumference, the lighter regions between the warts providing a distinctly reticulate pattern in surface view.

Sterile cells globose to subglobose, (20–)21–29(–33) × (12–)18–25(–26) µm, subhyaline to pale yellowish brown, wall 2–4 µm thick, homogenous, surface punctuate, warts 1–2.5 µm high.

Hosts
   
Host family: Poaceae
   
Host species: Eriachne festucacea F. Muell.

Distribution

States & Territories: WA

Comments

Tilletia geeringii is only known from the type specimen on E. festucacea, which is endemic to the Kimberley region of Western Australia and adjacent parts of the Northern Territory (Simon and Alfonso 2011). The spores of T. geeringii are morphologically similar to the spores of the T. mactaggartii and T. marjaniae, from which it differs in host range, and in the structure of the wall of sterile cells.