Centaurea calcitrapa

Star knapweed (Centaurea calcitrapa )

The Star knapweed (Centaurea calcitrapa ), also called Fußangel Knapweed, is a plant of the genus Centaurea (Centaurea ) in the sunflower family ( Asteraceae).

Description

The Star knapweed is a creeping - ascending, two-year hapaxanthe plant that reaches a height of from 10 to 100 cm. It is cobweb -like hairy and glabrous above. The stem grows erect or ascending and branched from the base of repeated sparrig so that there are zigzag curved branches. The leaves are colored green. The lower leaves are divided up to 8 inches long and pinnatisect that up to 2.5 cm long sections are denticulate and almost pungent. The flowers blossom together like brains. These are very numerous, sessile, axillary or terminal- colored and purple. The casing is bulb -shaped and up to 1 inch wide. The Hüllschuppen are dachig and have an up to 2.5 centimeters long, very strong, terminal, bent spine and on the side a few small teeth. All flowers are tubular, pale purple fünfzipflig and colored. The outer flowers are sterile and enlarged. The fruit is up to 3 mm long achene with a hair ring, a pappus absent.

Bloom time is from June to October.

Occurrence

The species occurs in South and South-East Europe and western Asia before, but was deported worldwide and is considered a weed. In Germany it is often distributed only as entrained plant. It grows in sunny and warm slopes, roadsides and waste places.

Documents

• Otto Schmeil, Jost hinge plates, Siegmund Seibold: Flora of Germany and neighboring countries, 93rd edition, Quelle & Meyer Verlag GmbH & Co., Wiebelsheim 2003, ISBN 3-494-01413-2.
• Hans -Joachim Zuendorf, Karl -Friedrich Günther, Heiko Korsch and Werner Westhus (eds.): Flora of Thuringia. Hawthorn -Verlag, Jena, 2006, ISBN 3-936055-09-2.
• Ehrentraud Bayer, Karl Peter Buttler, Xaver Finkenzeller, Jürke Grey: Plants of the Mediterranean ( The colored nature guide ). Mosaik Verlag GmbH, Munich 1986.