Sonchus oleraceus L.
Sonchus is the Greco-Latin name of the Sow Thistle.
Oleraceus is Latin and means pot herb or vegetable.
Other names:Annual Sowthistle
Summary:Common Sowthistle is an erect, hairless, branched annual or biennial herb about 1 m tall with hollow stems which have a milky sap. The basal leaves are up to 30 cm long, form a rosette and are soft and lobed or toothed. The stem leaves are somewhat smaller and stem clasping. The yellow dandelion-like flower heads are clustered, each about 2 cm in diameter, with all the florets having a radiating petal-like blade. These sprays of 'flowers' are at the ends of branches. The tiny fruits are short and flattened, topped by a tuft of fine soft bristles. Native to Europe, Asia and northern Africa, they are common weeds of pasture and waste land, but also invade bushland, particularly in damp areas. It flowers for much of the year but mainly in spring and early summer.
Two. Oval, 6-10 mm, tip flat to slightly indented. Base tapered. Hairless. Short merging stalk. The seedling has a short hypocotyl and no epicotyl.
First Leaves:Arise singly, round with slightly toothed and softly spined edges, 7-18 mm long with a stalk 5 mm long. Base tapered. Few, white, multicellular hairs on the top side. Later leaves are stalkless and lobed.
Leaves:Develops as a rosette about 250 mm in diameter. Exudes a sticky white sap when damaged.
Petiole - Broad on the lower leaves.
Blade - Dull green, thin, deeply and irregularly lobed or sharply toothed, 60-300 mm long x 10-150 mm wide, soft, edges scarcely prickly. End lobe wider than the side lobes. Side lobes usually point towards the base of the leaf. Edges of lobes toothed and softly spined. Tip pointed. Base indented.
Stem leaves - Alternate. Clasp stem with pointed tip lobes but do not continue down the stem as wings. Lower leaves deeply lobed or toothed, upper ones smaller and triangular with stem clasping, spreading lobes forming bracts below the flowering branches. Hairless.
Stems:Erect, 300-2000 mm tall, hollow, waxy bloom, round in cross section, fluted with lengthwise grooves, wingless. Hairless or a few glandular hairs especially near the top. Branch from the base and along their length. Often red, lengthwise stripes. Exudes a sticky white latex when damaged.
Flower head:Clusters of several heads on the ends of stems in a corymbose panicle to almost umbellate. Head (involucre) initially egg shaped and becoming conical, 10-25 mm diameter x 9-25 mm long with bracts and woolly at the base when young, otherwise hairless with several rows of unequal bracts.
Flowers:Yellow, thistle type.
Bracts - Hairless, unequal.
Florets - Yellow, all tubular, all with 'petals' (ligules). 'Petals' about the same length as the tube.
Ovary - Receptacle naked.
'Petals' - Yellow.
Fruit:Brown, elliptical to oblong achene, 2.5-3 mm long x 1 mm wide, flattened, 3-5 rough ribs per face with crosswise, wrinkles or stripes, between and on the ribs. Edges thickened, no wings. Fine hairs. Pappus of many, very fine, silky bristles and down like barbed hairs.
Seeds:Enclosed in the achene.
Key Characters:Stems leafy.
Leaves flaccid, scarcely prickly with acute appressed auricles, terminal lobe wider than those below it.
Florets all ligulate.
Achenes elliptic in outline, narrowed towards both ends, compressed, obtuse, ribbed lengthwise, ribs rugose, transversely wrinkled, not beaked, margin thickened, faces with 3-5 prominent ribs which are never raised to form small wings.
Pappus of numerous silky bristles intermixed with fine down like barbed hairs.
Adapted from J.M. Black, N.T. Burbidge and N.S. Lander.
Annual or short lived perennial. Seeds germinate from autumn to spring and it grows mainly in the cooler months. It usually flowers in spring and dies after flowering finishes in summer.
Flowering times:Mainly spring in western NSW.
Most of the year in SA.
June to December in Perth.
June to February in WA.
Seed Biology and Germination:Surface seed is short lived but buried seed will survive a few years.
Hybrids:Intermediate forms between Common Sowthistle (Sonchus oleraceus) and Rough Sowthistle (Sonchus asper) may occur.
Allelopathy:Population Dynamics and Dispersal:
Spread by seed that is mainly dispersed by wind.
Since it is palatable in the young stages it does not normally survive in pasture.
Increases in stubble mulching systems.
Origin and History:Europe, Asia and North Africa.
Distribution:ACT, NSW, NT, QLD, SA, TAS, VIC, WA.
In all parts of Tasmania.
Courtesy Australia's Virtual Herbarium.
Soil:Most soil types.
Plant Associations:Most communities.
Stems and root eaten by aboriginals. Leaves and shoots eaten as cooked vegetable.
Juice used in herbal medicine for curing ulcers and an extract used as a purgative.
Detrimental:Weed of crops, fallows, gardens, horticulture and disturbed areas.
Increases in stubble mulching systems.
Toxicity:Plants affected by aphids may cause photo sensitisation in cattle.
Management and Control:Establish competitive pastures and graze.
The leaves are hard to wet, so the addition of a wetting agent usually improves control by herbicides.
Manually remove isolated plants or graze the area to prevent seed set for several years.
Single plants may be sprayed with 50 mL glyphosate(450g/L) in 10 L water or wiped with a mixture 1 L glyphosate(450g/L) in 2 L water at any time before budding.
Spray small areas with a mixture of 100 mL of Tordon®75-D plus 25 mL wetting agent in 10 L of water in June each year. This will kill growing plants and leave a soil residue to control seedlings.
In bushland situations 4 L/ha 2,4-DB(400g/L) or 80 mL 2,4-DB(400g/L) plus 25 mL wetting agent in 10 L of water for hand spraying will provide reasonably selective control when applied in June. A repeat application may be necessary in late spring if a spring germination occurs.
Herbicide resistance:Biological Control:
Clammy Sowthistle (Sonchus tenerrimus) has wrinkled achenes that taper at the base.
Corn Sowthistle (Sonchus arvensis)
Native Sowthistle (Sonchus hydrophilus) has seeds(achenes) with hairy ribs, longer narrower leaves which are wavy or shallowly lobed rather than toothed.
Rough Sowthistle (Sonchus asper) has pricklier and more leathery leaves with a nearly straight leaf base. In the early stages they are very difficult to distinguish. In the rosette stage it has a less distinct petiole. The two species are often difficult to tell apart and occasional hybrids have been found.
Plants of similar appearance:Capeweed (Arctotheca calendula) has a light underside and darker upper surface on the leaf.
Common Sowthistle (Sonchus oleracea)
Dandelion (Taraxacum officinale)
Flatweed (Hypochoeris radicata)
Fleabane (Conyza spp.)
Indian Hedge Mustard (Sisymbrium orientale)
Ox tongue (Helminthotheca echioides)
Prickly Lettuce (Lactuca serriola)
Prickly Sow Thistle (Sonchus asper)
Rapistrum (Rapistrum rugosum)
Slender Thistle (Carduus spp.)
Smooth Catsear (Hypochoeris glabra)
Skeleton Weed (Chondrilla juncea) has backward pointing leaf lobes.
Wild Radish (Raphanus raphanistrum)
Wild Turnip (Brassica tournefortii)
References:Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P117. Photo.
Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P942.
Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P396, 398-399. Diagram.
Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P718. Photo.
Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P106-107. Photo.
Hyde-Wyatt, B.H. and Morris, D.I. (1975). Tasmanian weed handbook. (Tasmanian Department of Agriculture, Hobart, Tasmania). P34-35. Diagrams.
Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).
Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #1145.4.
Marchant, N.G., Wheeler, J.R., Rye, B.L., Bennett, E.M., Lander, N.S. and Macfarlane, T.D. (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P708.
Wilding, J.L. et al. (1987). Crop weeds. (Inkata Press, Melbourne). P64. Diagram. Photo.
Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.
Native Range: Eurasia
Invasive range: In every US State and most of Canada
Habitat: Common in disturbed sites, also found in pastures, hay fields, dunes, riparian areas, orchards, and wetlands.
Description: Leaves are lanceolate, with wavy margins, covered in spines on both the margins and beneath, and bluish-green in color. Grows yellow flowers resembling dandelions that sprout in clusters at the end of stems. Can reach up to 6 feet in height.
It is 1773. Captain Cook’s men, foraging, find a Sow Thistle at Queen Charlotte Sound in New Zealand. Which they proceed to devour along with several other “excellent vegetables,” invaders introduced from Polynesia: wild taro, two kinds of air potato, the paper mulberry, and the cabbage tree, a Cordyline. All but the last in that list go on to become invaders in North America. And the Age of Great Plant Hunters isn’t over yet.
Sow thistle can be found just about everywhere.
Less bitter than dandelion, sow thistle leaves are said to be a good source of vitamins A and C, thiamine, riboflavin, niacin, calcium, phosphorus, and iron. Young leaves provide substance and depth of flavor to other greens, and in salads the yellow flowers prove a bright addition. Are you intimidated by the prickly spines on the edges of the leaves? Stir-frying will soften them. Did a nibble on a leaf make you think it’s too bitter to eat? Simmer them for ten or so minutes––cooking gets rid of the bitterness. Old leaves also go well in soup. Grated nutmeg, butter, and broth marry nicely with this weed. The roots can be roasted, ground, and used as a coffee substitute.
According to New Yorker writer Jane Kramer the local word for sow thistle in Cumbria is crespina. Be careful of the spiky center rib, writes Kramer: “I regard the small scar that I got that day as a forager’s mark of initiation.”
Even in recipes, you can trace an invader’s history. The Cambridge World History of Food, says of Maori cuisine in New Zealand, “Of the European animals, the pig–well established and running wild by the early 19th century––was the earliest and most successful introduction . . . . In fact pork and white potatoes joined native puha (sow thistle) and sweet potatoes, foods from the sea, and birds from the forest as the Maori diet in the early decades of the nineteenth century.”
Eat The Weeds: Sow Thistle
To get the most out of harvesting sow thistle, its good to look for younger weeds, which are flavorful and best to harvest when they are about 4 to 12 inches high. Older plants can be simmered to reduce bitterness and soften the prickly spines.
Sow thistle is especially difficult to eradicate, as the white brittle roots can penetrate several feet into the soil, producing new plants from small root pieces.
Texas forager Merriwether Vorderbruggenlower picks buds before they open and places them in leftover pickle juice, letting them soak for six weeks. (We love the reuse of pickle juice!) Enjoy like capers.
Sautéed Wild Serralha
From Weird Combinations
The author describes a simple and mouth-watering Brazilian preparation, typically served with rice and beans, fried egg, and tomato salad (see above).
1 huge bunch of sow thistle, about two pounds
5 cloves garlic, minced
5 tbsp olive oil
Heat olive oil in a deep pan. Add garlic and sauté till fragrant and translucent. Add sow thistle, salt, and pepper. Toss. Cover pan and let it cook until volume is reduced to less than half.
Adjust flavor to your taste with more salt, pepper or olive oil.
The serralha bread shown at top is from Neide Rigo, author of the Brazilian blog Come-se. For those who speak Portuguese, an amazing culinary experience awaits. We look forward to translating and baking this; if any readers beat us to it, please let us know and we’ll publish your results.
Sow Thistle with Red Onion, Goat Cheese and Pine Nuts
From Foraging Foodie
1 bunch of sow thistle leaves (about one pound)
1 clove of garlic, minced
1/4 red onion, thinly sliced (or more if you like)
Goat cheese, crumbled
1/4 cup chicken broth
salt and pepper
Nutmeg to taste
Rinse, chop and boil the Sow thistle leaves for a few minutes. Drain. Heat olive oil in a big fry pan and saute the red onion for three minutes. Add minced garlic and saute for another minute. Lower the heat to medium and add the Sow thistle leaves while stirring (they will shrink so you can keep adding leaves). When they’re all shrunk, add some chicken broth and cover, simmer for ten minutes. Season with salt, pepper and nutmeg. Stir in a couple of table spoons of crumbled goat cheese, or to taste, and pine nuts.
Sow Thistle Lasagna
1 large onion, chopped
6 garlic cloves
1 pound canned whole tomatoes
9 lasagna pasta sheets
one pound of cooked sow thistle leave (can be sautéed as above)
1 pound ricotta cheese
1/4 pound shredded mozzarella cheese
Add oil to a pan and fry the onion until translucent, then add the garlic and as much of the dried basil and oregano as you like along with the tomatoes. Season well then bring to a simmer and mash the tomatoes. Cook for about 10 minutes.
Place a layer of lasagna sheets on the base of 9″ by 13″ pan (other sizes are fine as long as they fit the lasagna sheets). Add a layer of ricotta cheese on top, followed by a layer of tomatoes, and a layer of sow thistle greens. Repeat the process and cover the dish generously with a layer of shredded mozzarella cheese.
Cover the dish with foil and place in an oven preheated to 350° and bake for about 45 minutes. Remove the foil and return to the oven for 5 minutes to brown the top. Serve immediately.
Foraging foodie has a list of simple and tasty sow thistle recipes including Buttery Sow Thistle, Stir-fried Sow Thistle and Pork, and Sautéed Sow Thistle