Anthracocystis mutabilis (Syd.) McTaggart & R.G. Shivas

Synonyms

Sorosporium cantonense Zundel (as "cantonensis")
Sorosporium mutabile (Syd.) L. Ling
Sorosporium terrareginalense Zundel
Sporisorium mutabile (Syd.) Vánky
Sphacelotheca mutabilis Syd.
Sporisorium cantonense (Zundel) L. Guo

Description

Sori destroying the racemes, long-cylindrical, 5–13 mm long, 0.5–1.0 mm wide, partly hidden by leaf sheaths and spathae, at first covered by a brown peridium that ruptures from its apex exposing the dark brown semi-agglutinated to granular-powdery mass of spore balls and 1–3 long filiform columellae.

Spore balls globose, ellipsoidal, irregular, 40–120 × 40–80 µm, dark reddish brown to subopaque, composed of numerous readily separating spores.

Spores subpolyhedrally irregular to elongate, 13–18 (–20) × 10–15 µm, yellowish brown; wall unevenly thick, 0.5–1.5 (–2) µm, distinctly and rather densely verrucose, especially on the free surface; inner spores punctate-verruculose; spore profile smooth to wavy or finely serrulate.

Hosts
   
Host family: Poaceae
   
Host species: Cymbopogon aff. bombycinus (R.Br.) Domin
Cymbopogon obtectus S.T.Blake
Cymbopogon refractus (R.Br.) A.Camus

Distribution

States & Territories: NSW, QLD, WA

Comments

Three smut fungi, A. cymbopogonis-bombycini, S. lanigeri and A. mutabilis, have been recorded on Cymbopogon in Australia. Anthracocystis mutabilis is readily identified as it destroys the racemes and has comparatively large spores with unevenly thickened walls.