Ustanciosporium kuwanoanum (Togashi & Maki) Vánky

Synonyms

Sorosporium apparaoi G.K. Rao
Sorosporium kuwanoanaum Togashi & Maki
Thecaphora africana H. Scholz
Ustanciosporium tenellum R.G. Shivas & K. Vánky

Description

Sori in some or all flowers of a spikelet, swollen, forming a black mass of spore balls and spores on the surface of inner floral organs, 0.3–1.2 mm diam. or larger by confluence, at first hidden by the outermost glumes, later protruding or naked. Infection systemic; all spikelets of a plant affected.

Spore balls varying in shape and size, irregular, often elongate, 15–70 µm long, dark reddish brown to subopaque, composed of 2–20 (–25) spores that separate by pressure, or spores solitary.

Spores highly variable in shape and size, irregular, with 1 or several flattened sides separated by sharp edges, often elongate, with acute tips, more rarely globose, hemiglobose or ellipsoidal, (9–) 10.5–20.0 (–22) × 7–13 µm, yellowish to reddish brown, lacking hyaline appendages; wall uneven, 0.5–2.0 (–3) µm thick, thickest at the angles; surface irregularly minutely foveolate-reticulate; contact sides usually verruculose; spore profile smooth to very finely wavy.

Hosts
   
Host family: Cyperaceae
   
Host species: Cyperus tenellus L.f.
Scirpus antarcticus L.

Distribution

States & Territories: SA, VIC