Anthracocystis ovaria (Griffiths) McTaggart & R.G. Shivas

Synonyms

Sorosporium brachiariae J.C. Hopkins
Sorosporium brachiariae-ramosae K. Ramakr.
Sorosporium ovarium Griffiths
Sorosporium verecundum (Syd. & P. Syd.) Zundel,
Sphacelotheca diplospora var. verruculosa G.P. Clinton
Sporisorium ovarium (Griffiths) Vánky
Ustilago urochloana Zundel
Ustilago verecunda Syd.

Description

Sori in the flowers (ovaries) of all spikelets of an inflorescence, ±hidden by the floral envelopes, subcylindrical or with subacute tips, 2.0–3.5 mm long, 1.0–1.5 mm wide, at first covered by a light brown leathery peridium that ruptures irregularly from its apex exposing the chocolate-brown semi-powdery mass of spore balls and a columella with short branches, or 2 or 3 short filiform columellae.

Spore balls loose, many-spored, 45–130 × 35–100 µm or larger, reddish brown.

Spores subglobose, ovoid, broadly ellipsoidal or irregularly subpolyhedral, 8.5–11.0 (–12) × 8.0–10.5 µm, yellowish to reddish brown; wall uniformly c. 0.8 µm thick, densely and uniformly finely echinulate, causing the spore edge to appear finely serrulate.

Sterile cells few, in small irregular groups, in short chains or solitary, globose, ellipsoidal, flattened on contact sides, 9–18 µm long, hyaline; contents granular; wall 1.0–1.5 µm thick, smooth.

Hosts
   
Host family: Poaceae
   
Host species: Brachiaria piligera (F.Muell.) Hughes
Brachiaria pubigera (Roem. & Schult.) S.T.Blake

Distribution

States & Territories: NT, QLD