Sporisorium modestum (Syd.) H. Scholz

Synonyms

Sphacelotheca modesta (Syd.) Zundel
Ustilago modesta Syd.

Description

Sori in all flowers of an inflorescence, occupying the ovaries and the basal part of the inner floral envelopes, 1.5–2.5 mm long, 1.0–1.5 mm wide, apiculate, covered by a delicate yellowish peridium that flakes away exposing the blackish brown, initially agglutinated later dusty mass of spores mixed with sterile cells and a short (0.5–1.5 mm) irregular central columella.

Spores solitary at maturity, globose to broadly ellipsoidal, 11–14 × 9–12 (–13) µm, olivaceous brown, rather densely echinulate; spines thin, acute, 0.5–1.0 µm high.

Sterile cells in irregular groups; individual cells globose to ellipsoidal, 5.5–10.0 µm long, hyaline, thin-walled (c. 0.5 µm), smooth.

Hosts
   
Host family: Poaceae
   
Host species: Enneapogon avenaceus (Lindl.) C.E.Hubb

Distribution

States & Territories: NT