The Common Knapweed

The knapweed (Centaurea jacea) is a herbaceous plant of the composite family (Asteraceae Compositae). A synonym Centaurea thuillieri.

In the Netherlands (except Drenthe) and Flanders is a common plant of roadsides and other places ruderale.

The remaining plant is 30-70 cm high. The upper leaves are undivided and are alternately along the stem. The lower leaves are usually winding up veerspletig.

The flower heads are 2-4 cm wide. They consist of pink to red-purple tubular flowers. The edge of these flowers are sterile and enlarged. By increasing the side stand and they look like ray florets. Omwindselbladen in the upper half have a separate, prickly Appendix. The flowering period is from June until autumn.

It grows on a moist, moderately rich soil. One can often find the plant along roadsides and other grassy places more or less. The species has a preference for clay soils. The range consists of Eurasia, with an emphasis on temperate and southern regions.

Pollination is by insects. The plant has no self-fertilization. In Switzerland, the plant chosen for this reason an experiment in which fertilization rates between different sites was measured. It was noted that only 200 m standing plants is still 5% chance of pollination by bees and butterflies had social.

Under Dutch Beekeepers Association, the knapweed inspired by bumblebees and honeybees from the genera Andrena, Dasypoda, Halictus, Lasioglossum and Mega Chile.

It is the host for including Cochylis dubitana, Cochylis posterana, Ectropis crepuscularia, Eupithecia satyrata, Eupithecia subfuscata, Eupithecia Vulgate, light daguil (Heliothis viri Placa) and Malacosoma Castrense.



Source: http://nl.wikipedia.org/wiki/Knoopkruid


See also: International Flower Delivery, Florist