Microbotryum parlatorei (A.A. Fisch. Waldh.) Vánky


Ustilago parlatorei A.A. Fisch. Waldh.
Ustilago domestica Bref.
Ustilago lagerheimii Bref.


Sori in stems, petioles, leaves and flowers, often extensive and causing distortion and swelling of the infected parts, filling the tissues with a blackish purple powdery spore mass.

Spores globose, subglobose or sometimes ovoid, 11–15 (–16) × 11–14 (–16) µm, violet-tinted light reddish brown; wall reticulate, 5–8 meshes per spore diameter; meshes 1–2 µm wide; muri 1.0–1.5 µm high, in median view appearing spiny; sometimes the walls of the meshes are incompletely formed and the common points of the meshes appear as warts; in SEM the reticulum irregular in shape and size, subpolygonal to sometimes round, interspaces with clavate or rounded sometimes confluent warts.

Spore germination resulting in a 4-celled basidium bearing numerous lateral basidiospores.

Host family: Polygonaceae
Host species: Rumex obtusifolius L.


States & Territories: NSW