Microbotryum reticulatum (Liro) R. Bauer & Oberw.

Synonyms

Bauhinus reticulatus (Liro) Denchev
Ustilago controversa Cif.
Ustilago ravida Liro
Ustilago reticulata Liro
Ustilago utriculosa sensu Tul. & C. Tul.

Description

Sori in swollen and deformed flowers, affecting all in the inflorescence, filled with a brownish violet powdery spore mass; typically, only the distal half of the perianth remains intact. Infection systemic; all flowers of an infected plant affected; infected plants often rather stunted.

Spores globose, subglobose to ovoid, 9–15 × 9–12 µm, violet-tinted light reddish brown; wall 2–3 µm thick, coarsely reticulate, (2–) 3–4 meshes per spore diameter; meshes 2–4 µm wide; muri 1.0–1.5 µm high; in SEM interspaces densely verrucose-tuberculate.

Spore germination resulting in 4-celled basidia on which sessile basidiospores are produced laterally and terminally.

Hosts
   
Host family: Polygonaceae
   
Host species: Persicaria lapathifolia (L.) Gray

Distribution

States & Territories: NSW, QLD, VIC