Anthracocystis anthistiriae (Cobb) McTaggart & R.G. Shivas

Synonyms

Sorosporium anthistiriae (Cobb) L.Ling
Sporisorium anthistiriae (Cobb) Vánky
Tolyposporium anthistiriae Cobb
Tolyposporium anthistiriae Henn.

Description

Sori in scattered ovaries (awn present), cylindrical, often slightly bent, 10–30 mm long, 1.5–2.0 mm wide, at first covered by a yellowish peridium that ruptures longitudinally exposing the black granular-powdery mass of spore balls and several filiform columellae.

Spore balls rather permanent, ovoid to usually elongate or irregular, 30–170 µm long, reddish to blackish brown, composed of a few dozen to several hundred spores.

Spores dimorphic. Outer spores globose, subglobose, ovoid to slightly irregular, 9–14 × 8–12 µm, dark reddish brown; wall uniformly 1.0–1.5 µm thick; free surface densely and moderately coarsely verruculose-echinulate. Inner spores polyhedrally irregular, yellowish brown, thin-walled (c. 0.5 µm), apparently smooth.

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

Distribution

States & Territories: WA

Comments

The type specimen of A. anthistiriae could not be located in Australia or overseas (IMI, K). Many of the Australian specimens labelled as A. anthistiriae in BRIP, DAR and VPRI were found to represent A. walkeri, which has smaller sori (8–12 mm long and 1 mm wide) and shorter spore balls (not more than 80 µm long). Anthracocystis anthistiriae infects the ovaries leaving the awns of fertile spikelets intact, which also differentiates it from A. walkeri which destroys spikelets or the whole raceme together with the (lemma) awns of the fertile spikelets. An examination of the type specimen, if it can be located, is necessary to resolve a possible synonymy of the two taxa. However, this is further complicated by the later homonym Tolyposporium anthistiriae Henn., which is different from A. walkeri.