Doassansia alismatis (Nees) Cornu

Synonyms

Doassansia alismatis (Nees) C. Fisch
Doassansia alismatis (Nees) J. Schröt.
Perisporium alismatis (Nees) Fr.
Sclerotium alismatis Nees

Description

Sori in leaves initially as yellowish white, later pale to dark brown orbicular or elongate spots, 1–15 mm diam. (larger when coalesced), sometimes covering most of the leaf surface.

Spore balls embedded in the host tissue, appearing as numerous very minute raised dark brown dots, globose, ovoid or slightly irregular, 110–220 (–250) µm diam., composed of a central mass of spores surrounded by a cortex of 1 or, at least partly, 2 layers of sterile cells.

Spores globose, subglobose, ovoid or slightly irregular, subpolyhedral, 9.5–15.0 × 7–11 µm, yellowish hyaline; wall thin, c. 0.8 µm, smooth.

Cortical cells firmly united, without spaces between them, mostly radially elongate, polyhedral, irregular or occasionally subglobose or flattened, 8–25 × 5–13 µm, yellowish brown, with a smooth 1.0–1.5 µm thick wall.

Hosts
   
Host family: Alismataceae
   
Host species: Damasonium minus (R.Br.) Buch.

Distribution

States & Territories: NSW

Comments

Doassansia alismatis has only been collected once in Australia during investigations into potential biocontrol agents for the native marsh plant Damasonium minus, which has become an important weed of rice crops in New South Wales and northern Victoria (Pitt et al., 2004a, 2004b). An anamorph, Savulescuella alismacearum (Sacc.) Cif., has been reported overseas but probably refers to basidiospores germinated in situ (Lutman, 1910; Zambettakis, 1959).