Anthracocystis blakeana (Vánky) McTaggart & R.G. Shivas

Synonyms

Sporisorium blakeanum Vánky

Description

Sori destroying destroying the racemes, fusiform, 15–25 mm long, 0.5–1.5 mm wide, completely hidden by the tubuliform spatheole and also covered by a rather thick yellowish brown peridium on which numerous short or long fissures appear. Inside the spatheole and within the irregularly opened peridium, there is a black granular-powdery mass of spore balls and a long filiform columella.

Spore balls rather regular, globose, subglobose, ovoid, ellipsoidal, rarely slightly irregular, 50–90 × (40–) 50–70 (–90) µm, reddish brown, composed of a few tens of spores that separate by hard pressure.

Spores dimorphic. Outer spores rounded to subpolyhedrally irregular, 15–20 (–21.5) × 11.0–18.5 µm, medium reddish brown, with several large distinct irregular yellowish brown spots due to the irregularly thickened wall [0.5–2.0 (–2.5) µm thick], thickest at the angles; free surface of the outer spores c. 1.5 µm thick, including the blunt 0.5–0.8 µm high spines that, in surface view, appear as sparsely to moderately dense irregular warts; spore profile finely serrulate. Inner spores rounded, subpolyhedrally irregular, c. the size of the outer spores, subhyaline or yellowish brown-tinted; wall even to slightly uneven, 1.5–4.0 µm thick; contents finely granular.

Sterile cells absent.

Hosts
   
Host family: Poaceae
   
Host species: Schizachyrium fragile (R.Br.) A.Camus

Distribution

States & Territories: QLD

Comments

Due to the continued growth of the sorus within a relatively short tube of spatheole, the peridium becomes a crinkled irregular net with numerous irregular openings, apart from the 2 narrowing ends that remain closed. Anthracocystis blakeana has larger spores than A. abscondita which also occurs on Schizachyrium in Australia.