Sonchus oleraceus

Sonchus oleraceus is a species of flowering plant in the tribe Cichorieae of the family Asteraceae, native to Europe and Western Asia. It has many common names including common sowthistle, sow thistle, smooth sow thistle, annual sow thistle, hare's colwort, hare's thistle, milky tassel, milk thistle, and soft thistle.

Its specific epithet means "vegetable/herbal". The common name 'sow thistle' refers to its attractiveness to pigs, and the similarity of the leaf to younger thistle plants. The common name 'hare's thistle' refers to its purported beneficial effects on hare and rabbits.

Botanical characteristics
This annual plant has a hollow, upright stem up to 30 to 100 cm high. It prefers full sun, and can tolerate most soil conditions. The flowers are hermaphroditic, and common pollinators include bees and flies. It spreads by seeds being carried by wind or water.

This plant is considered an invasive species in many parts of the world, where it is found mostly in disturbed areas. In Australia it is a common and widespread invasive species, with large infestations a serious problem in crops.

Cuisine


Leaves are eaten as salad greens or cooked like spinach. This is one of the species used in Chinese cuisine as kŭcài (苦菜; lit. bitter vegetable). The younger leaves are less bitter and better to eat raw. Steaming can remove the bitterness of older leaves. The younger roots are also edible and can suffice as a coffee substitute.

Nutritive qualities
Nutritional analysis reveals 30 – 40 mg of vitamin C per 100g of plant, 1.2% protein, 0.3% fat, 2.4% carbohydrate. Leaf dry matter analysis per 100 g (likely to vary with growing conditions) shows: 45 g carbohydrate, 28 g protein, 22 g ash, 5.9 g fibre, 4.5 g fat; in all, providing 265 calories.

Minerals


 * Calcium: 1500 mg
 * Phosphorus: 500 mg
 * Iron: 45.6 mg
 * Magnesium: 0 mg
 * Sodium: 0 mg
 * Potassium: 0 mg
 * Zinc: 0 mg

Vitamins


 * A: 35 mg
 * Thiamine (B1): 1.5 mg
 * Riboflavin (B2): 5 mg
 * Niacin: 5 mg
 * B6: 0 mg
 * C: 60 mg

Herbalism
Sonchus oleraceus has a variety of uses in herbalism. It also has been ascribed medicinal qualities similar to dandelion and succory. The early Māori people of New Zealand are likely to have gathered it for food and medical use.

Native Americans had many uses for this plant. Pima used its gum as a "cure for the opium habit," as a cathartic, and as a food, where the "{l}eaves and stems {were} rubbed between the palms of the hands and eaten raw" and sometimes "boiled." The Yaqui used the plant as a vegetable, where the "{t}ender, young leaves boiled in salted water with chile and eaten as greens." The Kamia (Kumeyaay) "boiled {the} leaves {and} used {it} for food as greens." The {Houma} used it as an abortifacient where an "{i}nfusion of {the} plant {was} taken to 'make tardy menstruation come;'" an antidiarrheal; for children that were teething; and as hog feed.

The Samaritans eat the leafs of this bitter plant on the feast of passover. The bitter leafs are eaten together with Paschal lamb and unleavened bread, as dictated by the Bible (Exodus 12, 8): “ They shall eat the flesh that night, roasted on the fire; with unleavened bread and bitter herbs they shall eat it.” Thus, the Samaritans identify Sonchus oleraceus with the bitter herbs.