Sporisorium themedae (Duke) Vánky

Synonyms

Sphacelotheca themedae Duke

Description

Sori occupying entire racemes, elongate, c. 15 mm long and 1 mm wide, at first covered by a yellowish brown peridium that dehisces from its apex exposing a dark brown powdery mass of spores mixed with groups of sterile cells and a simple central columella tapering toward the apex; on rare occasions, columella bifurcate or with 1 or 2 short lateral branches.

Spores when mature solitary, globose, subglobose to ovoid, 9.5–12.0 × 8.0–10.5 µm, yellowish brown; wall uniformly c. 0.8 µm thick, moderately densely and finely verrucose-echinulate.

Sterile cells in irregular groups, readily separating; individual cells cells globose or ovoid, often collapsed, 10–15 µm long, pale yellowish brown, smooth, with homogeneous contents.

Hosts
   
Host family: Poaceae
   
Host species: Themeda triandra Forssk.

Distribution

States & Territories: NT, QLD, WA

Comments

Sporisorium themedae is similar to S. benguetense in having sori that occupy the racemes and have single unbranched columellae. However, the former has smaller spores.