a genus of cereal plants of the grass family Poaceae (Graminae).
oatgrass may cause ergotism (see rye ergot1) when infested with Claviceps purpurea.
cereal oats, a major feed for animals as grain hay or grazing crop. May cause poisoning by nitrite, a nutritional deficiency of magnesium leading to hypomagnesemia, or mycotoxicosis when the crop is infested with unspecified fungi. See also oat grain.