Sweet Vernal Grass

Sweet vernal grass (Anthoxanthum odoratum) is a short-lived perennial grass that grows in tufts. It has a strong smell due to the presence of coumarin. Coumarin can be converted to dicoumarol, a vitamin K antagonist, through the action of molds which is toxic to grazing livestock.

There have been several incidents of poisoning in cattle. The first was associated with ingestion of a contaminated bailed silage and the second a moldy round bale of hay.