Annual Sowthistle, common sow-thistle, hare’s lettuce, colewort, milk thistle
Description: summer annual place of origin: Europe
Urban habitat: grows best in rich soil in full sun but is common in neglected residential and commercial landscapes, minimally maintained parks, pavement openings and cracks, vacant lots, and rubble dumps.
Ecological function: disturbance-adapted colonizer of bare ground.
History: Sonchus oleraceus arrived early in North America after European colonization and was commonly used to feed cattle. The common name sowthistle refers to its attractiveness to pigs. Parts of the plant have been used medicinally to stimulate menstrual flow, alter liver function, combat cancer, treat warts and reduce fever. The leaves applied as a poultice has been found to reduce inflammatory swelling. The leaves have a mild agreeable flavor and contain many nutrients when consumed as salad greens or cooked like spinach. Its cooked stems are similar to asparagus or rhubarb. The milky sap found inside the stems have been used as a chewing gum by the Maoris of New Zealand and has been used in other parts of the world as a cure for opium addiction.