Sporisorium mitchellii (Syd. & P. Syd.) Vánky


Ustilago mitchellii Syd. & P. Syd.


Sori occupying the entire raceme, cylindrical, c. 3–6 mm long and 1 mm wide, at first covered by a brown peridium that disintegrates from the apex exposing a blackish brown semi-powdery spore mass mixed with sterile cells, surrounding a simple 3–6 mm long central columella.

Spore balls many-spored, loose, irregular, readily disintegrating.

Spores globose, subglobose, ovoid, ellipsoidal to subpolyhedrally irregular, 9.0–13.5 × 7–11 µm, reddish brown; wall uniformly c. 1 µm thick, densely and finely echinulate.

Sterile cells subglobose, ellipsoidal or irregular, with flattened sides, 8–16 (–20) µm long, pale yellowish brown, solitary, in chains or in irregular groups, collapsed in old specimens; wall 1.5–2.5 µm thick, smooth.

Host family: Poaceae
Host species: Iseilema dolichotrichum C.E.Hubb.
Iseilema holmesii S.T.Blake
Iseilema membranaceum (Lindl.) Domin
Iseilema vaginiflorum Domin


States & Territories: NT, QLD, SA, WA


Sporisorium mitchellii is the most widespread and commonly collected of the four species of Sporisorium which infect Iseilema in Australia.