The scale bar (Centaurea calcitrapa) is an annual or biennial plant that belongs to the composite family (Compositae or Asteraceae). It is a plant of dry food and calcareous soil. The plant is native to Europe but is also distributed in North America. In the Netherlands, the plant in southern Limburg. The species is on the Dutch Red List of plants as very rare and very much reduced.
The plant is 15-60 cm tall and forms a rosette. The rising and twisting stems are almost bare, furrowed and branched shrub. The lower leaves are broken and some parts of the upper leaves are lanceolate or linear and have a prickly point. During flowering the lower leaves are already dead.
Trip lime flowers from July to September with pink or purple, sometimes white flowers. Inflorescence a head. The flower heads are 6-8 mm in diameter and 1.5 to 2 cm long. The carpels have a straight top, above the foot are slightly constricted above and have a prickly appendix. At the top is one of the outer carpels 1 to 2.5 cm long spine.
The fruit is 2.5 to 3.5 mm long, white or brown nut without gestreepd Pappus. Ants on the fruit is a sandwich.
See also: International Flower Delivery, Florist