Onopordum acanthium

Scottish Thistle at the Leipzig floodplain forest.

The ( Common ) called cotton thistle ( Onopordum acanthium ), even cancer thistle, woolly thistle, spasm thistle, a plant species in the subfamily Carduoideae is within the sunflower family ( Asteraceae).

Description

It is a biennial herbaceous plant. In the first year a rosette is formed. In the second year it grows to imposing stature heights of 0.5 to 3 meters and plant diameters of 1.5 meters. It is covered with loose and spinnwebigen hair. The up to about 1 meter long leaves are ovate, toothed or pinnately lobed short, wavy and thorny. Your wide running down the wing edges form thorny stems.

The terminal, large, 5 cm wide flower heads are spherical. They are surrounded by thorny bracts. There are only disc florets present that are purple. After pollination, the flower heads swell and produce 8500-40000 seeds.

The scientific name Onopordum acanthium means " thorny Eselblähung ", derived from the effect of the plant on donkeys.

Ecology

The Common thistle is a two year Hemikryptophyt and forms the first year a rosette to 1 m wide with tiefreichendem root factory. The whole plant appears densely gray - white tomentose by total internal reflection of light.

The leaf blades of the stems serve to stabilize the large plant in the storm and water drainage directly into the root zone. The thorns keep cloven-hoofed animals from the food. All these features can be interpreted as xerophytic adaptations to dry habitats.

The flowering period extends from July to August. The flowers are part of the " basket of flowers " type. Because of up to 12 mm long corolla tube only langrüsselige visitors can get to the nectar. The up to 5 mm long stylus branches spread not, but turn to maturity solely occupied with their papillae outer edges. This different behavior of a Asteracee leads to lower evaporation in the scar area.

Visitors are next to Bee relatives, wasps and butterflies and hoverflies, which collect the pollen from the protruding from the corolla anthers.

The fruits are achenes oil-rich, they carry a wenigreihigen, feathered and hygroscopic ( only in dry spreading ) Pappus and therefore spread as Schirmchenflieger. These will Adhäsionsausbreitung in damp weather held and spread by ants and spread as Kulturflüchter by humans. The seeds are long-lived.

Occurrence

The thistle is native to sub-Mediterranean continental areas in Europe and Asia Minor ( Mediterranean, Asian regions of Russia ) and comes in addition to their countries of origin isolated against throughout Europe. In the United States, the entrained ( invasive plant ) plant is considered as a weed. It prefers dry summers on sandy clay and limestone soils. So she comes in Germany and neighboring countries as a ruderal plant, for example, on the wayside (hence " Wegdistel " in Dutch ), on traffic islands, dry meadows and fields before. In parts of its habitat it is an endangered plant.

After Ellenberg she is a full- light plant, a heat indicator, sub-continental spread, a weak acid to weak base pointer, an outspoken nitrogen pointer, and a heat -seeking Verbandscharakterart thistle companies ( Onopordion acanthii ).

Use

Parts of the plant are of value to humans, such as the flower heads and the bottoms of artichokes similar as a vegetable, the stems (peeled) like asparagus or rhubarb cooked in water. The seeds (25% oil) can be edible oil (even lamp suitable ) presses. The flowers contain Onopordopikrin, flavone glycosides and tannins. The cardiotonic effect of the drug attributed is questionable, recent studies do not exist anyway.

History

Pictures

Scottish Thistle in the first year

Inflorescence and leaf

Inflorescence