Sonchus

Sonchus is a genus of flowering plants in the tribe Cichorieae within the family Asteraceae and are commonly known as sow thistles (less commonly hare thistles or hare lettuces). Sowthistles are annual, biennial or perennial herbs, with or without rhizomes and a few are even woody (subgenus Dendrosonchus, restricted to the Canary Islands and Madeira).
Description
The genus is named after the Ancient Greek for such plants. 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 latex. Flower heads are yellow and range in size from half to one inch in diameter; the florets are all of ray type. Sonchus fruits are single-seeded, dry and indehiscent. Sow thistles are common roadside plants, and while native to Eurasia and tropical Africa, they are found almost worldwide in temperate regions.
Mature sow thistle stems can range from 30 cm to 2 m (1 to 6 ft) tall, depending upon species and growing conditions. Coloration 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 milk thistle more commonly refers to the genus Silybum.
Species
The following 106 species are accepted by Plants of the World Online .
Sonchus acaulis
Sonchus x aemulus
Sonchus afromontanus
Sonchus araraticus
Sonchus arboreus
Sonchus arvensis
Sonchus asper
Sonchus x beltraniae
Sonchus berteroanus
Sonchus bipontini
Sonchus bornmuelleri
Sonchus bourgeaui
Sonchus brachylobus
Sonchus brachyotus
Sonchus brassicifolius
Sonchus briquetianus
Sonchus bupleuroides
Sonchus camporum
Sonchus canariensis
Sonchus capillaris
Sonchus cavanillesii
Sonchus congestus
Sonchus crassifolius
Sonchus daltonii
Sonchus dregeanus
Sonchus erzincanicus
Sonchus esperanzae
Sonchus fauces-orci
Sonchus fragilis
Sonchus friesii
Sonchus fruticosus
Sonchus gandogeri
Sonchus gigas
Sonchus gomeraensis
Sonchus grandifolius
Sonchus gummifer
Sonchus heterophyllus
Sonchus hierrensis
Sonchus hotha
Sonchus hydrophilus
Sonchus integrifolius
Sonchus jacottetianus
Sonchus jainii
Sonchus x jaquiniocephalus
Sonchus kirkii
Sonchus laceratus
Sonchus latifolius
Sonchus leptocephalus
Sonchus lidii
Sonchus lobatiflorus
Sonchus luxurians
Sonchus macrocarpus
Sonchus maculigerus
Sonchus malayanus
Sonchus marginatus
Sonchus maritimus
Sonchus masguindalii
Sonchus mauritanicus
Sonchus x maynari
Sonchus megalocarpus
Sonchus melanolepis
Sonchus micranthus
Sonchus microcarpus
Sonchus microcephalus
Sonchus nanus
Sonchus neriifolius
Sonchus novae-zelandiae - also known as Kirkianella novae-zelandiae
Sonchus x novocastellanus
Sonchus obtusilobus
Sonchus oleraceus
Sonchus ortunoi
Sonchus palmensis
Sonchus palustris
Sonchus parathalassius
Sonchus pendulus
Sonchus phoeniciformis
Sonchus pinnatifidus
Sonchus pinnatus
Sonchus pitardii
Sonchus platylepis
Sonchus x prudhommei
Sonchus pruinatus
Sonchus pustulatus
Sonchus radicatus
Sonchus regis-jubae
Sonchus regius
Sonchus x rokosensis
Sonchus x rotundilobus
Sonchus x rupicola
Sonchus saudensis
Sonchus schweinfurthii
Sonchus sinuatus
Sonchus sosnowskyi
Sonchus splendens
Sonchus stenophyllus
Sonchus suberosus
Sonchus sventenii
Sonchus tectifolius
Sonchus tenerrimus
Sonchus transcaspicus
Sonchus tuberifer
Sonchus ustulatus
Sonchus webbii
Sonchus wightianus
Sonchus wildpretii
Sonchus wilmsii
Invasive
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, may deplete soil water of land left to fallow, 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, and this lettuce-relative is edible and nutritious to humans—in fact this is the meaning of the second part of the Latin name of the common sow thistle, oleraceus. Attempts at weed control by herbicidal use, to the neglect of other methods, may have led to a proliferation of these species in some environments.
Cultivation
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 including Celypha rufana and the broad-barred white, grey chi, nutmeg, and shark moths. The fly Tephritis formosa is known to attack the capitula of this plant.
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 pūhā or rareke (raraki) it is a traditional food eaten in New Zealand by Māori. When cooked the flavour is reminiscent of chard
Uses
The greens were eaten by the indigenous people of North America. Edible raw when young, the older greens can also be eaten after cooking briefly.
References
External links
Low, Tim. Wild Herbs of Australia and New Zealand. Rev. ed. Angus and Robertson, 1991. .
Washington State Noxious Weed Control Board
Perennial Sowthistle Fact-Sheet
Botanical.com — sow-thistles
Tamar Valley Weed Strategy SOW and PRICKLY SOW THISTLES
Asteraceae genera
Herbs
Leaf vegetables
New Zealand cuisine
Taxa named by Carl Linnaeus
Māori cuisine