Welcome to the MedLibrary.org Wikipedia Supplement on Sonchus -- Please Click to Return to Front Page

Sowthistles
3 stages of flowering
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Asterales Family: Asteraceae Tribe: Cichorieae Genus: Sonchus L.
Species
Sonchus asper - spiny sow thistle Sonchus arvensis - field or perennial sow thistle Sonchus dregeanus Sonchus integrifolius Sonchus kirkii - puha or rauriki Sonchus nanus Sonchus oleraceus - common sow thistle Sonchus wilmsii - milk thistle

Sow thistles (less commonly hare thistles or hare lettuces) are annual herbs in the genus Sonchus, after their Ancient Greece name. All are characterized by soft, somewhat irregularly lobed leaves that clasp the stem and, at least initially, form a basal rosette. The stem contains a milky sap. Flower heads are yellow and range in size from half to one inch in diameter; the florets are all of ray type. Sow thistles are common roadside plants, and while native to Eurasia and tropical Africa, they are found almost worldwide in temperate regions. Like the true thistles, sow thistles are in the family Asteraceae.

Mature sow thistle stems can range from 30 cm to 2 m (1 to 6 feet) tall, depending upon species and growing conditions. Colouration ranges from green to purple in older plants. Sow thistles exude a milky latex when any part of the plant is cut or damaged, and it is from this fact that the plants obtained the common name, "sow thistle", as they were fed to lactating sows in the belief that milk production would increase. Sow thistles are known as "milk thistles" in some regions, although true milk thistles belong to the genus Silybum.

Sow thistles have been used as fodder, particularly for rabbits, hence the other common names of "hare thistle" or "hare lettuce". They are also edible to humans as a leaf vegetable; old leaves and stalks can be bitter but young leaves have a flavour similar to lettuce. Going by the name puha or rareke (raraki) it is frequently eaten in New Zealand as a vegetable, particularly by the native Māori. When cooked it tastes a little similar to chard.

In many areas sow thistles are considered noxious weeds, as they grow quickly in a wide range of conditions and their wind-borne seeds allow them to spread rapidly. Sonchus arvensis, the perennial sow thistle, is considered the most economically detrimental, as it can crowd commercial crops, is a heavy consumer of nitrogen in soils, and can regrow and sprout additional plants from its creeping roots. However, sow thistles are easily uprooted by hand, and their soft stems present little resistance to slashing or mowing. Most livestock will readily devour sow thistle in preference to grass.

Sonchus tenerrimus and Sonchus oleraceus infest many crops in Italy, especially in the Southern area of the peninsula. Here they are also considered good taste edible plants and they are cooked with spaghetti.

Sow thistles are common host plants for aphids. Gardeners may consider this a benefit or a curse; aphids may spread from sow thistle to other plants, but alternatively the sow thistle can encourage the growth of beneficial predators such as hoverflies. In this regard sow thistles make excellent sacrificial plants. Sonchus species are used as food plants by the larvae of some Lepidoptera species including Broad-barred White, Grey Chi, The Nutmeg and The Shark.

References

Wikimedia Commons has media related to:

Sonchus

• Everitt, J.H.; Lonard, R.L., Little, C.R. (2007). Weeds in South Texas and Northern Mexico. Lubbock: Texas Tech University Press.  ISBN 0-89672-614-2
• Low, Tim. Wild Herbs of Australia and New Zealand. Rev. ed. Angus and Robertson, 1991. ISBN 0-207-17001-0.

External links

• Washington State Noxious Weed Control Board
• Perennial Sowthistle Fact-Sheet
• Botanical.com — sow-thistles

Wikipedia content modification information:

• This page was last modified on 29 September 2008, at 19:47.

Wikipedia Authorship and Review

Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.

Wikipedia Usage Guidelines

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "Sonchus".

The URL for this specific entry is:

• http://medlibrary.org/medwiki/Sonchus

All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.