Sporisorium iseilematis-vaginiflori Vánky

Description

Sori occupying the entire racemes, cylindrical, 3–6 mm long, 1.0–1.5 mm wide, at first covered by a thick pale brown peridium that dehisces early exposing a blackish brown powdery mass of spores mixed with sterile cells, surrounding an unbranched 3–6 mm long central columella.

Spore balls many-spored, loose, separating early into individual spores.

Spores slightly subpolyhedrally irregular, more rarely subglobose, ellipsoidal or elongate, 10.5–16.0 (–17.5) × 9.5–13.0 µm, reddish brown; wall even to slightly uneven, 0.5–1.0 µm thick, finely and densely echinulate; surface granulate between the spines in SEM.

Sterile cells in irregular groups; individual cells globose, ovoid to irregular, with 1 or several flattened sides, usually smaller than the spores, (6–) 7–15 × 6–13 µm [globose cells 6–12 µm diam.], subhyaline to pale yellowish brown; wall 0.5–1.5 µm thick, smooth.

Spore germination resulting in a long simple aseptate 2.5–3.0 µm wide germ tube that elongates into a 110–130 µm long apical part filled with protoplasm, leaving behind a long empty tube with retraction septa. Primary septa and basidiospores not seen.

Hosts
   
Host family: Poaceae
   
Host species: Iseilema holmesii S.T.Blake
Iseilema vaginiflorum Domin

Distribution

States & Territories: QLD, WA

Comments

Sporisorium iseilematis-vaginiflori has comparatively large spores (10.5–17.5 µm long), including many that are ellipsoidal or elongate.