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, puha, hare's colwort, hare's thistle, milky tassel, milk thistle, and soft thistle.

Description

This annual plant has a hollow, upright stem up to 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.

Etymology

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.

Invasiveness

Annual sowthistle is considered an invasive species due to its rapid growth, prolific seed production, and wide dispersal. The plant thrives in disturbed environments, such as roadsides and agricultural fields, spreading aggressively through wind-dispersed seeds. It forms dense populations that outcompete native vegetation by quickly establishing in open areas, particularly after soil disturbance. Sowthistle's resilience to various soil types and its ability to reseed itself make it difficult to control in many regions.
In Australia it is a common and widespread invasive species, with large infestations a serious problem in crops.

Uses

The leaves are eaten as salad greens or cooked like spinach. This is one of the species used in Chinese cuisine as kŭcài. 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.

Nutrition

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 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 : 1.5 mg
  • Riboflavin : 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. When the plant was introduced to New Zealand, the Māori people found it similar to and as palatable as their native pūhā or S. kirkii, thus also picked up S. oleraceus for similar 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 "leaves and stems rubbed between the palms of the hands and eaten raw" and sometimes "boiled." The Yaqui used the plant as a vegetable, where the "tender, young leaves boiled in salted water with chile and eaten as greens." The Kamia "boiled leaves for food as greens." The Houma used it as an abortifacient where an "infusion of plant 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 : “ 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.