Red clover (
Trifolium pratense) is a short-lived, cool season perennial which is widely distributed. It has trifoliate leaves that are pubescent and alternate with a pale, inverted, crescent-shaped mark on the mid-upper surface. Inflorescences, terminal on main and axillary stems, consist of many ovoid, compound racemes with numerous pink or purple florets.
Toxic components
Under certain conditions,
T. pratense can become infested with a fungus,
Rhizoctonia leguminicola, which appears as black and brown spots on the top side of the clover leaves. While on the clover,
R. leguminicola produces slaframine, a type of mycotoxin that causes excessive salivation (slobbers) in horses grazing it. It appears in pastures during periods of hot and humid weather.
White clover (Trifolium repens), alfalfa (
Medicago sativa), and
alsike clover (Trifolium hybridum) can also, on occasion, become infected with the
R. leguminicola fungus.
