Urocystis glabella Vánky & R.G. Shivas

Description

Sori in the leaves and leaf sheaths, as linear grey blisters up to 3 cm long, or as irregular swellings 2 mm wide, at first covered by the epidermis which ruptures exposing the black semi-agglutinated to powdery mass of spore balls.

Spore balls globose, ovoid, ellipsoidal to slightly irregular, 25–60 × 20–40 µm, medium to dark reddish brown, composed of (0–) 1–6 (–8) spores and a usually completely enveloping layer of sterile cells.

Spores subglobose, ovoid, ellipsoidal, usually irregular, rounded-subpolyhedral, often with 1 or several flattened sides, 13.0–16.0 (–18.5) × 9.5–14.5 µm, medium to dark reddish brown; wall uniformly c. 0.5 µm thick, smooth.

Sterile cells globose, ellipsoidal, often irregular, 8–25 µm long, yellowish brown, usually not collapsed; wall uneven, 1.5–5.0 µm thick, smooth, thinner on the free surface.

Spore germination not known.

Hosts
   
Host family: Hypoxidaceae
   
Host species: Hypoxis glabella R.Br.
Hypoxis pusilla Hook.

Distribution

States & Territories: SA, VIC

Comments

Three other species, U. hypoxis Thaxter, U. thaxteri Vánky  and U. aurea Vánky, also occur on Hypoxis, but none is known from Australia. Urocystis thaxteri and U. hypoxis have spore balls composed of significantly more spores than those of U. glabella. The South African species, U. thaxteri has balls of (3–) 5–25 (or more?) spores, and the North American U. hypoxis has balls of (1–) 3–10 (–15) spores. The spores, sterile cells and spore balls of U. glabella are larger than those of the U. aurea (from India), which has spore balls 20–40 × 20–32 µm and spores 9.5–16.0 × 8–12 µm.