Smooth Sow-thistle - Sonchus oleraceus

Main features

  • Basal rosette of leaves

  • Leaves deeply lobed giving the appearance of pairs of leaflets

  • Fine spikes along the edge of the leaves

  • Common garden and agricultural weed - likes a moist sunny spot

  • Yellow flowers similar in shape and colour to Dandelion

  • Possible confusion with Groundsel, which does not have spikes along its leaf edge

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Smooth Sow-thistle - Sonchus oleraceus

Edible plant - novice

Other common names Sow-thistle, Hare's Colwort, Milky Tassel, Swinies, Hare's Thistle, Hare's Lettuce, Thallak, Common Sow-thistle

 

Scientific name meaning The genus name Sonchus is of Greek origin and means "hollow". This is in reference to the Sow-thistle's hollow stem. Interestingly for what is now considered a weed, the species name oleraceus is a Latin word meaning "from the vegetable garden"

Season Spring to Autumn

Habitat - where will I find it? Smooth Sow-thistles can be found in most temperate regions, but is native of Europe and Asia. It can be found in garden borders, plant pots, agricultural land, and wasteground. It likes sunshine and moist soils 

Description - what does it look like? Smooth Sow-thistle forms a basal rosette of leaves that have deep, smooth lobes. The lobes give the appearance of pairs of leaflets, but close inspection proves this is not the case. 

The edges of the leaves are covered with very small fragile "spikes". 

The plant throws up a flower stalk between June and August. The leaves on the flower stalk have an elongated teardrop shape and wrap around the stem almost like a shirt collar. The flowers are similar in appearance and colour to Dandelions. When the older leaves are damged, they exude a white sap or “latex”

Possible lookalikes Groundsel is a potential poisonous lookalike, but its leaves do not have fine spikes around the edge. Dandelions and members of the true thistle family, Cirsium, could also be confused with Smooth Sow-thistle, but both of these are edible and the latter has much tougher spikes and leaves

Use as a food Smooth Sow-thistle is best eaten before flowering, after which time the plant becomes bitter. Young leaves can be eaten raw in salads, or steamed and used in the same way as spinach. The leaves of the basal rosette tend to have more spikes, but are generally less bitter. The stems can also be used like asparagus, but are far superior if the other layer of skin is removed first

Use in herbal medicine Smooth Sow-thistle has been used for a number of ailments including fevers, slow or late menstruation and diarrhoea. The latter is interesting, as juice from the stem is thought to have cathartic properties, and therefore cause the evacuation of the bowels. Overuse is cautioned as colic and tenesmus are potential side effects. 

Poultices have been made from leaves, while the latex has been used to treat warts. 
If you are suffering from any ailment or need medical advice, please see your General Practitioner

Hazards Excessive consumption of stems can lead to colic and tenesmus (recurrent diarrhoea)

Importance to other species The flowers provide a source of nectar for pollinators during the summer months. It is grazed upon by rabbits, deer, and cattle, and, as its common name suggests, is a particular favourite of pigs

Always stay safe when foraging. You need to be 100% sure of your identification, 100% sure that your foraged item is edible, and 100% sure that you are not allergic to it (it is good practice to always try a small amount of any new food you are consuming). If in doubt, leave it out!