Cirsium arvense

Creeping Thistle ( Cirsium arvense)

The Creeping Thistle ( Cirsium arvense) or creeping thistle is a plant which belongs to the sunflower family ( Asteraceae). It falls on mainly because of their spiny leaves and their violet colored flowers. They are found from June to end of September flourishing on - road and field margins. That is why it is often referred to as " weed ".

Description

The creeping thistle is a perennial herbaceous plant that reaches the plant height of 30 to 150 centimeters. She trains horizontally elongated, creeping root sprouts. The stem is rich leafy, usually branched panicle and not winged. The leaves are serrated and have a sinuate spiny ciliation on. The soft to rigid spines are about 5 mm long and are pointed. Upper hand, but the leaves are not prickly.

The 2 cm wide flower heads contain about 100 hermaphrodite, vormännliche single flowers. But there are also purely female plants with smaller brains and only 2 to 3 mm long corolla lobes. Thus the plant is gynodiözisch.

Your color is Blütenkronensaum fünfspaltig to the bottom. The flower is colored reddish to purple. The flowering period extends from July to October.

It has a feathery pappus.

Occurrence

The Creeping Thistle is mainly found along roadsides and waste places in all of Central Europe. They rarely grows at altitudes above 2000 meters. She likes especially dry locations, and occasionally we also find them in humid, semi- shady places. It is also commonly found in thickets and hedges.

Ecology

The Creeping Thistle is in Central Europe, a so-called Apophyt, as originally native to dry forest frontier locations sort moved to anthropogenic locations than in central Europe about 7,000 years ago, forests were cleared by people in order to make room for farmland. These locations were more open than most natural and they were disturbed regularly and thus offered the creeping thistle optimal living conditions.

The Creeping Thistle is a root bud Geophyt and a deep-rooting, which drives deep roots to 2.8 m. The flowers smell like honey. The style branches are occupied on the outside tightly with Fegehaaren. This growing out pen brush pushes the pollen out of the deflating inward stamen tube. The nectar increases in until about 10 mm long corolla tube to the exit. This makes it accessible to all kinds of insects, especially butterflies, the plant is an important source of nectar. In bad weather, spontaneous self-pollination takes place in the hermaphrodite flowers. In the flowers cynarin is included (1,3- O- caffeoylquinic acid ).

The fruits are achenes with hygroscopic hair calyx ( pappus ): There is therefore a Schirmchenflieger. Its sink rate is only 26 cm / second, so flight distances over 10 km are possible upwind. The fruits are ripe in August to October, each already about four weeks after flowering. The plant is in terms of their siting very demanding, only at suitable locations germinate their seeds.

The vegetative propagation of this kind is done by root shoots that emerge from the deep in the ground lying nearly horizontally extending runners roots. It is therefore far from a pioneer roots showing on fields and pastures dreaded 'weed'. Even from small choppy Wurzelstückchen can drive out new plants.

On stems of this plant it is not unusual to about 2 cm thick bile, caused by the larvae of Distelbohrfliege ( Urophora cardui ).

This species is extremely variable in differences in plant height, the design of the leaves and the size of the head. It was therefore divided into numerous subspecies and varieties that are difficult to separate, however.

The rust fungus Puccinia punctiformis attacks the creeping thistle and is therefore used successfully in North America and New Zealand for biological pest control of creeping thistle.

Pictures

Creeping Thistle before flowering

Creeping Thistle

Creeping Thistle - Pappus

Fruit stand of creeping thistle

Swell

• Creeping Thistle. In: FloraWeb.de.
• David J. Keil: Cirsium. In: Flora of North America Editorial Committee ( eds.): Flora of North America North of Mexico. Volume 19: Magnoliophyta: unranked, part 6: Asteraceae, part 1 ( Mutisieae - Anthemideae ), Oxford University Press, New York / Oxford et al 2006, ISBN 0-19-530563-9, p 109, (online ) (English).
• Ruprecht Duell, Herfried Kutzelnigg: Pocket Dictionary of Plants in Germany and neighboring countries. The most common central European species in the portrait. 7, revised and expanded edition. Quelle & Meyer, Wiebelsheim 2011, ISBN 978-3-494-01424-1, pp. 222-224.