Sporisorium andropogonis (Opiz) Vánky

Synonyms

Cintractia andropogonis (Opiz) Kochman
Cintractia ischaemi (Fuckel) Syd. & P. Syd.
Sorosporium baluchistani S. Ahmad
Sphacelotheca andropogonis (Opiz) Bubák
Sphacelotheca bothriochloae Wang
Sphacelotheca bothriochloae-intermediae (Padwick) Naras.
Sphacelotheca chloridis Mundk.
Sphacelotheca heteropogonis-triticei L. Ling
Sphacelotheca ischaemi (Fuckel) G.P. Clinton
Uredo (Ustilago) andropogonis Opiz (as "andropogi")
Ustilago bothriochloae-intermediae Padwick
Ustilago cylindrica Peck
Ustilago ischaemi Fuckel

Description

Sori usually destroying the entire inflorescence, rarely confined to the spikelets, cylindrical or bifurcate at their distal part, 15–70 mm long, 1–10 mm wide, partly hidden by the terminal leaf sheath, at first covered by a well-developed yellowish brown peridium that ruptures irregularly and flakes away exposing the dark brown semi-agglutinated to powdery mass of spores and groups of sterile cells surrounding a simple or ramified irregular columella of the length of the sorus, the remnants of the floral axis and branches. Infection systemic.

Spores when young in loose irregular spore balls, 40–160 µm long, when mature solitary, globose, ovoid, ellipsoidal to slightly irregular, 7.5–11.0 × (6.5–) 7–10 µm, light olivaceous brown; wall uniformly 0.5–1.0 µm thick, densely punctate-verruculose; spore profile smooth to wavy, in SEM spores minutely echinulate, between the spines finely and densely verruculose.

Sterile cells in irregular groups or chains among the spores and also forming the peridium, globose to irregularly polygonal, flattened on contact sides, 6–16 (–22) µm long, subhyaline to yellow-tinted, with numerous droplets, collapsed in old specimens; wall uniformly 0.5–1.0 µm thick, smooth.

Spore germination resulting in 4-celled basidia on which lateral and terminal basidiospores are produced.

Hosts
   
Host family: Poaceae
   
Host species: Bothriochloa bladhii (Retz.) S.T.Blake
Bothriochloa decipiens C.E.Hubb.
Bothriochloa pertusa (L.) A.Camus
Dichanthium sp.
Heteropogon contortus (L.) P. Beauv. ex Roem. & Schult.

Distribution

States & Territories: NSW, NT, QLD, WA

Comments

Sporisorium andropogonis destroys the entire inflorescence of its hosts, leaving a simple or branched columella. On Heteropogon contortus it can be differentiated from S. contortum which has smaller spores (5.5–8.0 × 5–7 µm).