In this condition, cows bled to death after consuming hay made from spoilt sweet clover. Warfarin is a derivative of dicoumarol, an anticoagulant originally discovered in spoiled sweet clover. Males are found on mint and sweet clover. Preferentially collects pollen from clover and sweet clover (Fabaceae). The identity of the anticoagulant substance in spoiled sweet clover remained a mystery until 1940. Exotic plant species include leafy spurge, Canada thistle and sweet clover. Himalayan blackberry, reed canary grass, and sweet clover are introduced species. The Femco Farms grew oats, barley, corn, alfalfa, sweet clover, rye, and flax. Adults primarily feed on nectar from various plants, particularly sweet clover, goldenrod, and Brazilian pepper. Sweet clover is an indigenous wild ground cover in the county. The name "sweet clover" varies orthographically ("sweet-clover", "sweetclover").