Silybum marianum

Milk thistle is an upright herb that can grow to be tall and has an overall conical shape. The largest specimens have hollow stems. The leaves are oblong to lanceolate and long and typically pinnately lobed, with spiny edges like most thistles. The flower heads are 4 to 12 cm long and wide, of red-purple colour. They flower from June to August in the North or December to February in the Southern Hemisphere. ==Distribution and habitat==

Silybum marianum is native from around the Mediterranean and much of Europe to Central Asia and India; in Africa it reaches as far south as Ethiopia. It is possibly native near the coast of southeast England. S. marianum has been widely introduced outside its natural range, for example into North America, Hawaii, Australia, New Zealand, and Colombia where it is considered an invasive weed. It also spreads invasively in almost all of Europe as a consequence of field cultivation. Silybum marianum establishes itself in sunny, warm ruderal meadows in regularly disturbed places such as rubble deposits, at the foot of south-exposed walls or villages and on urban fallow land or on cattle pastures. However, it does not prefer dry, stony soils. Milk thistle has been potentially observed to modify fire regimes in its invasive range. Its invasion into new habitats may also be encouraged by fire. ==Cultivation==

Milk thistle is an adaptive crop with low requirements. It is mainly cultivated as a medicinal plant but it is also sometimes used as a food source. It's mainly cultivated in Europe but also in Asia and North America. Milk thistle is a biennial plant, it is normally grown as an annual plant, which simplifies cultivation. When the main requirements of the plant are met, then the milk thistle will blossom in the first year. == Chemistry ==

Traditional milk thistle extract is made from the seeds, which contain approximately 4–6% silymarin. The extract consists of about 65–80% silymarin (a flavonolignan complex) and 20–35% fatty acids, including linoleic acid. Silymarin is a complex mixture of polyphenolic molecules, including seven closely related flavonolignans (silybin A, silybin B, isosilybin A, isosilybin B, silychristin, isosilychristin, silydianin) and one flavonoid (taxifolin). == Toxicity ==

Milk thistle based supplements have been measured to have the highest mycotoxin concentrations of up to 37 mg/kg when compared to various plant-based dietary supplements. Use of milk thistle may cause stomach upset and produce allergic reactions in some people. Animal toxicity Because of nitrate == Uses ==

Although potentially allergenic, the leaves and stems can be gathered ahead of bloom, the spines removed, and boiled with salt. The roots are edible raw or roasted and the flower head can be cooked like globe artichoke. Silymarin is extracted from the milk thistle seeds and available as a standardized extract. In 2019, Cancer Research UK stated: "We need a lot more research with reliable clinical trials before we can be sure that milk thistle will play any part in treating or preventing cancers." ==References==