Sowthistle is valued today, especially in England, as a veterinary herb, and for the treatment of fevers, high blood pressure, heart disorders, and other complaints. Centaurus is the classical name of a plant fabled by Ovid to have cured a wound in the foot of Chiron, one of the Centaurs of Thessaly. Centaurea includes the cornflowers, knapweeds, and starthistles. Starthistles and knapweeds are among the most notorious members of this genus. Yellow starthistle is an erect, much-branched annual, with stems having longitudinal wings formed by downward extension of the leaf bases.
Leaves are entire, gray and densely covered with cottony hair.
The entire plant is poisonous to horses. A stricken animal becomes depressed and may die of starvation or thirst. Yellow starthistle seed is a common impurity in alfalfa seed because they are nearly the same weight and are difficult to remove. Everist, S.L. 1979. Poisonous Plants of Australia, 2nd ed.