Tilletia horrida Takah.


Neovossia horrida (Takah.) Padwick & A. Khan


Sori ±destroying the ovaries, completely concealed by the coriaceous lemma and palea.

Spores globose, subglobose or ellipsoidal, 24–33 × 22.0–26.5 µm, yellowish to dark and almost chocolate-brown, with irregular 1.5–3.0 µm high warts, subacute or blunt in optical median view; in surface view appearing as darker irregular areas, 6–10 per spore diameter, often with 2 or several warts irregularly confluent.

Sterile cells globose, ovoid to slightly irregular, 22–36 × 14–24 µm, hyaline; wall 1.5–5.0 µm thick, smooth.

Host family: Poaceae
Host species: Oryza sativa L.


States & Territories: QLD


Tilletia horrida has been considered a synonym of T. barclayana (Bref.) Sacc. & P.Syd. based on their morphological similarity and cross-inoculation capabilities (Tullis & Johnson, 1952). Whitney (1989) was unable to repeat the inoculation experiments and suspected that the inoculum used by Tullis & Johnson (1952) was contaminated with T. pennisetina Syd. [= T. barclayana]. Furthermore, the host of the type of T. barclayana is Pennisetum (subfamily Bambusoideae), which is not closely related to Oryza (subfamily Panicoideae). Rice kernel smut was considered to be of little importance in northern Queensland (Tonello, 1980, as T. barclayana).

The presence of the infection is usually revealed by the dirty floral envelopes caused by the liberated spores.