Sowthistle

Introduction

The hollow stem yields a white, milky juice said to be eaten by sows to increase the flow of their milk. The Latin name of the genus ‘sowthistle’ is Sonchus meaning ‘hollow’.

There are many species of Sonchus (Sonchus spp.) – all are edible and most are indistinguishable in appearance – but the two most commonly used for food and medicine are smooth sowthistle (S. oleraceus) and prickly sowthistle (S. asper).

Sowthistles are sometimes confused with dandelions, because of the appearance of their bright yellow flowers and green spiny leaves.

The plant has a complicated relationship with humans. It has flourished in the path of human progress to become a common weed and wild edible. Along the way, some people have become devoted to its tender young leaves and juicy stem, while others have found its bitterness less agreeable.

Common Name

Smooth Sowthistle and Prickly Sowthistle.

Scientific Name

Smooth Sowthistle: Sonchus oleraceus.
Prickly Sowthistle: Sonchus asper.

Family

Compositae.

Botanical Description

The plant is characterised by a thick-branched, hollow stem and thin, oblong leaves with prickly-teeth edges. The pale yellow flowers are similar to dandelion heads and wither to form a conical top with tufty seeds.

Status

Annual, native to Britain, Ireland, Europe, Asia and North Africa.

Habitat

Prefers roadsides, wastegrounds, river banks and sea shores.

Parts Used for Food

Leaves, stem and flowers.

Harvest Time

Spring to Autumn.

Food Uses of Sowthistle

It has been used as a salad and potherb since the days of our early ancestors. The younger plants are mildly bitter and quite succulent; older plants are bitter and tough.

The leaves and stems of both species can be cooked like vegetables, added to stir fries and stews. The juicy stem should be milked before cooking because the juice can turn parts of the plant brown.

Nutritional Profile of Sowthistle

Sow-thistle has four times more antioxidant compounds than red wine and twelve times more antioxidants than black tea. It is rich in essential fatty acids and minerals and nutrients like zinc, manganese, copper, iron, calcium and fibre.

Its traditional use as an ingredient in spring dishes eaten for health and vitality is supported by its high content of vitamins A, B, C and K.

Per 100g fresh weight of various sowthistles contain between 30–60mg of vitamin C; smooth sow thistle has been shown to contain up to 800mg of vitamin A.

Sowthistle Recipes

Herbal Medicine Uses of Sowthistle

The medicinal virtues of smooth sowthistle (S. oleraceus) were believed to be similar to dandelion (Taraxacum officinale). Its juicy stem oozes a creamy milk like dandelion, which was used as a cure for warts.

Sowthistle was also used as a herbal remedy to hasten childbirth, treat skin and eye problems, and freshen foul breath.

Other Uses

The fluffy seeds were once used to stuff pillows and mattresses.

Safety Note

Smooth sowthistle is said to be more toxic than other species of sowthistle; a white latex produced from the plant is mildly poisonous to lambs and horses, and the roots are said to induce abortion.

References

Grieve M. A Modern Herbal Vol 2 (I-Z): The Medicinal, Culinary, Cosmetic and Economic Properties, Cultivation and Folk-Lore of Herbs, Grasses, Fungi, Shrubs, & Trees with All Their Modern Scientific Uses. Dover Publications; 1971.

Quattrocchi U. CRC World Dictionary of Medicinal and Poisonous Plants: Common Names, Scientific Names, Eponyms, Synonyms, and Etymology (5 Volume Set). CRC press; 2012.

Watts D. Dictionary of Plant Lore. Elsevier; 2007.

Kallas J. Edible Wild Plants: Wild Foods from Dirt to Plate. Gibbs Smith; 2010.

Awaad AS, Almoqren SS, Safhi AA, Zain YM, El-meligy RM, Al-asamary FA. Gastroprotective extracts of Sonchus oleraceus L. Published online November 27, 2018. Accessed December 10, 2018. http://www.freepatentsonline.com/10137162.html

Hatfield G. Hatfield’s Herbal: The Secret History of British Plants. Penguin; 2008.

Sánchez-Mata M de C, Tardío J, eds. Mediterranean Wild Edible Plants: Ethnobotany and Food Composition Tables. Springer; 2016. doi:10.1007/978-1-49393329-7

Kuhnlein HV, Turner NJ. Traditional Plant Foods of Canadian Indigenous Peoples: Nutrition, Botany and Use. Routledge; 1991.

Wiersema JH, Leon B. World Economic Plants: A Standard Reference. CRC Press; 2013.

Comment

  1. Hello, wondering about the toxicity (to humans) of smooth sow thistle and where I can find out how much is safe to consume – I have lots growing in my flower beds and would love to use it in smoothies and salads. What does “more toxic than other species of sow thistle” mean practically? Thank you in advance.

    • You cannot see wild food plants in the same way as farmed plants. Small amounts of a wide diversity of plants is the way to go. The toxicity refers to the latex in the stems, so leaf and leaf blades are fine, just don’t eat large amounts of the stems/stalks.

  2. Kiri, this article states the roots may induce abortion and are not listed as edible. So if that’s the only info available, use that info as you will. But I would suggest a foraging or specific book on this plant, try the library.

  3. We have to put pressure on governments to stop spraying to kill all these noxious weeds that have been the mainstay of food and medicine for our ancestors and could be for the present population as well.
    By destroying all the free wild edibles we become reliant on the elite few that stock questionable foodstuffs on our grocery store shelves.

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