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Thistle - Variegated
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Variegated Thistle
Silybum marianum
Origin: Native to Europe |
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Growth habit, Goulburn River National Park. Image by Tony
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Family:Asteraceae
Form: Annual
Growth Habit: Variegated thistle is a widespread weed in Tasmania and generally occurs in pasture, crops, roadsides and neglected areas. In soils of high fertility it can build up toxic levels of nitrates. Seeds generally germinate in autumn, depending upon moisture levels, however germination at low levels may occur at other times of the year.The young plant develops into a rosette, usually up to 1 metre in diameter, but plants are capable of growing larger under ideal conditions. The leaves exhibit striking white variegations, hence the plant's name. A large specimen in flower is a very striking plant. The tall upright flower stem comprises many branches and is produced in late winter. This usually reaches up to 1 metre but may grow considerably larger.
Dispersal: Variegated thistles are spread entirely by seed. The seeds are equipped with a small pappas, or parachute of hairs, however they are not disbursed over long distances by wind. Most seed falls within a few metres of the parent. Livestock, particularly sheep, also spread seed in their wool.
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Status: Silybum marianum is declared as Secondary Weeds under the Noxious Weeds Act 1964.
Weed Impact: Variegated thistle is a serious weed in Tasmania, particularly in the lower rainfall areas of the midlands. Infestations can be very dense and may totally dominate pasture or a crop. It is also a widespread and troublesome weed of roadsides
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Edible Uses
Root - raw or cooked. A mild flavour and somewhat mucilaginous texture. When boiled, the roots resemble salsify (Tragopogon hispanicus). Leaves - raw or cooked. The very sharp leaf-spines must be removed first, which is quite a fiddly operation. The leaves are quite thick and have a mild flavour when young, at this time they are quite an acceptable ingredient of mixed salads, though they can become bitter in hot dry weather. When cooked they make an acceptable spinach substitute. It is possible to have leaves available all year round from successional sowings. Flower buds - cooked. A globe artichoke substitute, they are used before the flowers open. The flavour is mild and acceptable, but the buds are quite small and even more fiddly to use than globe artichokes. Stems - raw or cooked. They are best peeled and can be soaked to reduce the bitterness. Palatable and nutritious, they can be used like asparagus or rhubarb or added to salads. They are best used in spring when they are young. A good quality oil is obtained from the seeds. The roasted seed is a coffee substitute.
Medicinal Uses
Astringent; Bitter; Cholagogue; Diaphoretic; Diuretic; Emetic; Emmenagogue; Hepatic; Homeopathy; Stimulant; Stomachic; Tonic.
Blessed thistle has a long history of use in the West as a remedy for depression and liver problems. Recent research has confirmed that it has a remarkable ability to protect the liver from damage resulting from alcoholic and other types of poisoning. The whole plant is astringent, bitter, cholagogue, diaphoretic, diuretic, emetic, emmenagogue, hepatic, stimulant, stomachic and tonic. It is used internally in the treatment of liver and gall bladder diseases, jaundice, cirrhosis, hepatitis and poisoning. The plant is harvested when in flower and dried for later use. Silymarin, an extract from the seed, acts on the membranes of the liver cells preventing the entry of virus toxins and other toxic compounds and thus preventing damage to the cells. It also dramatically improves liver regeneration in hepatitis, cirrhosis, mushroom poisoning and other diseases of the liver. German research suggests that silybin (a flavonoid component of the seed) is clinically useful in the treatment of severe poisoning by Amanita mushrooms. Seed extracts are produced commercially in Europe. Regeneration of the liver is particularly important in the treatment of cancer since this disease is always characterized by a severely compromised and often partially destroyed liver. A homeopathic remedy is obtained from equal parts of the root and the seed with its hulls still attached. It is used in the treatment of liver and abdominal disorders.
Other Uses
A good green manure plant, producing a lot of bulk for incorporation into the soil
Notes: A locally common weed of roadsides, neglected land and stream banks. African Olive produces fruit that are usually smaller and less fleshy than those of plants cultivated for edible olives and olive oil.
References:
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Weeds Committee
