Anthracocystis fallax (R.G. Shivas & J.H. Cunnington) McTaggart & R.G. Shivas


Sporisorium fallax R.G. Shivas & J.H. Cunnington


Sori destroying destroying the entire inflorescence, broadly fusiform, elongate-ovoid or cylindrical, c. 50 mm long and 5 mm wide, at first concealed by the leaf sheath and covered by a thick greyish peridium, later usually laterally protruding, the perdium rupturing and exposing the dark brown powdery mass of loose spore balls and several long simple filiform columellae.

Spore balls globose, subglobose to ovoid, 30–85 × 30–65 µm, dark brown, semi-permanent.

Spores dimorphic. Outer spores globose, subglobose to subpolyhedrally irregular, 6–10 × 6–8 µm, dark reddish brown; wall 1–3 µm thick, smooth to densely verruculose on the free surface. Inner spores globose, subglobose to subpolyhedrally irregular, often angular, 8–12 × 7–10 µm, pale yellowish brown to medium reddish brown, densely punctate-verruculose; wall 0.5–1.0 µm thick.

Sterile cells not seen.

Host family: Poaceae
Host species: Chrysopogon fallax S.T.Blake
Chrysopogon latifolius S.T.Blake


States & Territories: NT, QLD, WA


While the sori of A. fallax are similar to those of A. tumefaciens, the former has permanent spore balls and dimorphic, often angular spores. By contrast, A. tumefaciens has spore balls that readily separate by pressure and spores of one type that are mostly rounded rather than angular.