Bauerago cyperi-lucidi (J. Walker) Vánky

Synonyms

Ustilago cyperi-lucidi J. Walker

Description

Sori in swollen nutlets, filled with a light ochraceous yellow powdery mass of spores exposed following the rupture of the pericarp.

Spores subglobose, ovoid to slightly subpolyhedrally irregular, (15–) 17–24 (–26) × (12–) 16–20 (–24) µm, very finely and minutely reticulate, 10–15 meshes per spore diameter; wall 2.5–4.0 µm thick, including the reticulum; muri 1–2 µm high.

Infection systemic; all inflorescences of a plant and all nutlets in an inflorescence affected.

Hosts
   
Host family: Cyperaceae
   
Host species: Cyperus lucidus R.Br.

Distribution

States & Territories: ACT, NSW, QLD, TAS, VIC

Comments

During the period 1802–1805, the renowned British botanist Robert Brown, while collecting specimens of Cyperus lucidus near Port Jackson, Sydney, unknowingly gathered some smutted inflorescences. More than 150 years later the eminent Australian mycologist John Walker discovered the smut, which he named Ustilago cyperi-lucidi (Walker, 1971), parasitising the seeds in some of Robert Brown’s original specimens held in the Herbarium, Royal Botanic Gardens, Kew.

Bauerago cyperi-lucidi was the first smut fungus collected in Australia. It is difficult to detect in the field, and it appears that all collections have been identified initially by examination of inflorescences in botanical specimens. Walker (1971) highlighted the potential hazard of inconspicuous diseases in botanical taxonomy by suggesting that varieties of C. lucidus described in the literature may have resulted from morphological differences in nut shape and floret appearance between infected and healthy plants.