Sonchus oleraceous is delicate and beautiful plant. It is traditionally known all over the world for its nutritional and medicinal values. However, with increasing habitat destruction and pollutions this plant is currently living under stressed conditions that may push it towards extinction. The word Sonchus refers to hollow stem and Oleraceous refers to the delectable nature. It has medicinal properties similar to that of Dandelion and Succory. Leaves are used in salad in some parts of the world. Sonchus oleraceous belongs to family Asteraceae- the family of Daisy.
Habit and Habitat
Sonchus oleraceous is an erect annual or biennial herb that grows 30-110 cm high. It exudes latex if damaged. The plant used to grow during winter in India about a decade ago but now it is found the year round. It grows in moist soil in fields, pastures along roadsides, gardens and edges of yards, construction sites, waste land and disturbed areas. It is considered that this plant is adapted to a number of environments and grows well at low and high elevations in the tropics. It often grows in irrigated lands (Holm et al., 1997).
Weber, 2003 has reported that it is a wide spread weed. It is invasive in natural habitats as it grows in dense patches that crowd our native plants. However, it is rare in India and cannot be considered as invasive here. It is a shade tolerant pioneer plant species which establishes itself in disturbed areas.
Wagner et al. 1999 have reported that it is naturalized in a variety of habitats in Hawaii. Smith has reported that this plant is naturalized in clearings and cultivated areas and along forest trails up to 900m from sea level in Fiji. In New Guinea it is a weed of gardens and crop fields.
The plant Sonchus oleraceous is an annual plant. It is herb, tap rooted, rhizomatous or stolonoferous. The stem is erect, branched, and glabrous. Leaves are basal and cauline, peteolate, petioles usually winged, and blades oblong, oblanceolate, margins dentate or prickly. Inflorescence is head born in corymbiform to sub-umbelliform. Involucres are companulate, apices acute; receptacles are flat to convex, glabrous. Corollas are yellow or orange. Flowers are hermaphrodite, commonly pollinated by bees and flies. These are Heads with strap-shaped flowers, several on sometimes glandular stalks in an open, flat- or round-topped inflorescence, relatively small, commonly 1.5-2.3 cm wide in flower; involucres 9-14 mm tall; involucral bracts lanceolate, tapering to a slender tip at the apex, glabrous except for some spreading, gland-tipped hairs; ray flowers yellow. Fruits are achenes reddish-brown, strongly compressed, ovoid, lateral margins very thin with narrow wing; 0.08-0.1 in. (2-3 mm) long, 1 mm wide; light brown. 3 (rarely 4 or 5) prominent ridges on the face of the fruit, smooth between ridges. Pappus often tangled and holding several achenes in a cluster; more or less deciduous. A single plant may produce up to 8,000 seeds. Seed is able to germinate all year round over a broad range of temperatures and is favored by light, with emergence highest in seed present on the soil surface. Resistance to herbicides such as chlorsulfuron and atrazine has led to Sowthistles, including Sonchus oleraceous, being the target of biological control programs overseas and in Australia. Preliminary surveys for suitable control agents found two potential organisms: a rust fungus and eriophyid mite.
Sonchus spp. is pioneer species, invading natural habitats and disturbed sites (Zollinger and Parker 1999). Wind-dispersed seeds enable long distance travel (Zollinger and Parker 1999). Their rapid germination facilitates rapid establishment in diverse habitats (Zollinger and Parker 1999).
Sonchus has five angled hollow stem which exudes latex or whitish milk if damaged. The stem is dark green. A mature plant may be 30 to 110 cm in height. First leaves are round with slightly toothed margins with a few spines. They have sparse hairs on the upper leaf surface. Mature leaves are thin, soft and light green in colour.
Nomenclature and Common Names
It is reported that Sonchus oleraceous was named by Carolus Linnaeus in his book “Species Plantarum” in 1753. Sonchus means “hollow”. It is a Greek name for sow thistle. The Greek epithet “oleraceous” means “kitchen vegetable”. Its common names popular in different parts of the world are – Pualele in Hawaii; sow thistle, hare’s thistle and Hare’s Lettuce in USA; rauriki, pororua, puwha in Maori; Cerraja, diente de leon lechaso in Colombia; Leche in Bolivia and Qarasapi in Quechua. In India it is considered to be a close relative of Taraxacum sp. Here it is variously known in different regional languages. In French it is known as Laiteron commun, Lastron piquant. In Spanish it is known as Cerraja, Morraja and Nilhue.
It is typically found at an altitude of 0 to 4,653m. It is found in India, Europe, Australia, Middle East, North and South America, Mediterranean, North Africa, Atlantic Island etc. In India it is found in waste land, near margins of buildings, along roadsides and in neglected areas. It is reported that this plant is native to Europe (Wagner et al.1999) Eurasia and Northern Africa. However, it has been naturalized in India and appears here and there as a native plant.
In traditional western medical systems, the plant is considered as abortificent. Its extract is considered to have anti-cancer, anti-diarrheal, anti-inflammatory properties. It is reported to have blood purifying and tranquillizing properties.
In Turkey, the stem juice is used as cathartic. In China, it is considered that its juice clears infections and can be taken to cure opium addiction. It is digestive, purgative, diuretic. Paste of roots and leaves is used as febrifuge. In China, it is applied to stop bleeding, as tooth-ache remedy and as vermicide.
In other traditional medical systems, it is considered that its extract clears heat toxins, invigorates blood and stops bleeding, cools the blood, corrects linear imbalances and poor digestion.
In England, it is used to treat high blood pressure. The juice of the plant in distilled water is used for all hot inflammations, eruptions etc. In China the extract of the plant is used to treat appendicitis, sore throat, ear infections, infectious hepatitis, cirrhosis, jaundice, and liver dysfunctions, abscess, boils, carbuncles, caked breasts, uterine bleeding and irregular menses, coughing up blood, hematuria etc.
In U.S.A. its extract is used for the treatment of infectious hepatitis, cirrhosis, warts, and liver dysfunctions. In New Zealand the plant extract is taken to treat burning stomach, dyspepsia and other stomach problems. There, it is used also for the treatment of ear infections, other infections, and to check unwanted pregnancy. There the plant was once used by Captain Cook for scurvy. There it is also used to treat scorpion bite, abscess, and as blood purifier. In Germany, the plant extract is used in the treatment of cancer.
Nicholas Culpepper, an English Botanist (18 Oct. 1916 – 10 Jan. 1654) has recommended applications of this plant for the treatment of number of ailments like urinary stones, stopping of urine, urinary obstructions, easy and speedy delivery etc. Some of Nicholas Culpepper’s prescriptions are mentioned below –
1. Juice of the plant in distilled water is good for all hot inflammations, eruptions, and etching of the hemorrhoids.
2. It is wonderfully good for women to wash their faces with, to clear the skin and to maintain its luster.
3. Its extract is good for hot stomach.
4. Extract of the plant mixed with the bitter almond oil and pomegranate skin if applied topically can cure deafness.
Sow-thistle is a favourite food for rabbits and poultry and it is also used as fodder for cattle. The white latex is suspected of being mildly poisonous and cases of poisoning of lambs (Somalia) and horses (Australia) have been attributed to Sonchus oleraceous.
The leaves taste mild to quite bitter. Leaves contain per 100 g edible portion: water 87 g, energy 110 kJ (26 kcal), protein 3.2 g, carbohydrate 1.8 g, fibre 3.3 g, Ca 32 mg, Mg 76 mg, P 58 mg, Fe 3.8 mg, Zn 0.8 mg, carotene 16 mg, ascorbic acid 78 mg (Guil-Guerrero,J.L.,Giménez-Giménez, A., Rodríguez-García, I. & Torija-Isasa, M.E., 1998).
A study of chemical constituens of the extract of the whole plant reveals that it contains following nutrients- minerals and vitamins-
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
· Brooker,S.G., et al. 1987.New Zealand’s Medicinal Plants. Rev. ed. Aukland: Reed Books.
· Haselwood, E.L. and G.G. Motter, eds. 1983. Handbook of Hawaiian Weeds. 2nd eds. Honolulu: University of Hawai’I Press.
· Kaaiakamanu, D.M.1922. Hawaiian Herbs of medicinal value.(Trans. By Akaiko Akana) Rutland, VT:.Charles E. Tuttle Comapany
· Moerman, Daniel E. 1986. Medicinal Plants of Native America. Volumes one and two. Nn Arbor, MI.: University of Michigan Museum of Anthropology.
· Wolf MA(1999).“Winning the war on weeds”: The essential gardener guide to weed identification and control. (Kangaroo Press: East Roseville, Australia)
· Zollinger, R.K., and R. Parker. 1999. Sowthistles. In: Sheley, R.L. and J.K. Petroff (eds.). Biology and management of noxious rangeland weeds. Oregon State University Press, Corvallis, Oregon. 438 pp.
· Charles Darwin Research Station. 2005. CDRS Herbarium Records.
· Wagner, Warren L./Herbst, Derral R./Sohmer, S.H.1999. Manual of flowering plants of Hawalii. Honolulu. 1919 pp.
Sonchus oleraceous,weed, nutrirional and medicinal value, Africa, U.S.A., weed, noxious, Nicholas Culpepper
Image 4: credit USDA