Macalpinomyces arundinellae-setosae R.G. Shivas & Vánky

Description

Sori in some ovaries of an inflorescence, cylindrical, 5–13 mm long, c. 0.5 mm wide, protruding beyond the glumes, covered by a pale yellowish brown peridium that dehisces from its apex exposing a dark brown semi-agglutinated mass of spores and sterile cells.

Spores subglobose to irregularly subpolyhedral, 6.5–9.0 × 6.5–8.5 µm, brown; wall uniformly c. 0.5 µm thick, punctate to verruculose-echinulate.

Sterile cells globose, subglobose or ellipsoidal, often in large groups (hundreds of cells), 5–10 µm diam., mostly with a spherical vacuole c. 2.5 µm diam., hyaline; wall uniformly thin, smooth.

Hosts
   
Host family: Poaceae
   
Host species: Arundinella nepalensis Trin.
Arundinella setosa Trin.

Distribution

States & Territories: NT, QLD

Comments

Macalpinomyces arundinellae-setosae is similar to Sporisorium arundinellae (Bref.) Vánky (type on Arundinella sp., India) in that it infects ovaries and has small spores (less than 10 µm diam.). The most obvious difference is that the sori of S. arundinellae are much shorter (2–3 mm) than those of M. arundinellae-setosae. Vánky & Shivas (2005) have provided a key to the species of smut fungi on Arundinella.