Centaurea jacea
Meadow knapweed (Centaurea jacea )
The meadow knapweed (Centaurea jacea ), also called Common knapweed, is a plant that belongs to the genus of knapweed (Centaurea ) from the subfamily of Carduoideae in the family Asteraceae (Asteraceae).
- 6.1 Notes and references
Description
This perennial herbaceous plant reaches a height of 30 to 70 cm. The upper leaves are undivided and alternate. The lower leaves sinuate - pinnatifid.
The flower heads are 2-4 inches wide and consist of 60-100 violet tubular flowers, of which the rand union greatly enlarged and are sterile. The Hüllblattanhängsel are clearly separated and cover the following bracts completely. These are black -brown to whitish, entire or fringed slashed and roundish. The fruits have no pappus.
The plant contains tannins.
It flowers from June to October. Fruit ripening is from August to October.
Ecology
The Meadow knapweed is a perennial Hemikryptophyt ( stem plant). Vegetative propagation by root sprouts is possible.
There are flowers from the "basket flower - type" before. The plant is dreihäusig ( triözisch ) that is next to plants with hermaphrodite flowers that stand by greatly enlarged ray flowers and stunted nectaries, there are also purely male and purely female plants. There are many pollinators observed, such as: bees, bumble bees, butterflies and hoverflies. The maximum flower visiting starts at 15 clock. Supposedly self-pollination be possible by curvature of the stylus.
The achenes can be spread by the wind without pappus, but at best, wind spreader. Mainly occurs randomly spread by grazing animals besides spread by ants.
Occurrence
The species is widespread in Eurasia, with a distribution area in the central and southern areas. As the site semi-dry grasslands, meadows, pastures and roadsides are preferred with clay soils.
System
The species is very variable and is considered to be poorly understood. It forms hybrids, especially with the blackish knapweed (Centaurea nigrescens ). Some of the following subspecies could be those hybrids.
- Comb scales Meadow knapweed (Centaurea jacea subsp subjacea ( Beck) HYL. )
- Fiederschuppen Meadow knapweed (Centaurea jacea subsp macroptilon ( Borbás ) Hayek )
- Light shed Meadow knapweed (Centaurea jacea subsp gaudinii ( Boiss. & Reuter ) Gremli )
- Ordinary meadow knapweed (Centaurea L. subsp jacea jacea )
- Narrow- leaf meadow knapweed (Centaurea jacea subsp angustifolia)
Revision of Centaurea jacea group in Germany
Now first results of a revision were submitted for the families of this form rich kind in Germany, but still provisional. It turns out that fertile hybrids occur between virtually all types of Centaurea jacea group, some as " stabilized" of which can be viewed. This was attributed to species rank. In addition, there are numerous, obscure hybrid complexes in which can not be determined which species were involved in detail. The section " Jacea " within the genus Centaurea decomposes now into several separate part only provisionally named species:
- Eastern Narrow- knapweed (Centaurea pannonica subsp. Pannonica )
- Western Narrow knapweed (Centaurea pannonica subsp. Approximata )
- Low meadow knapweed (Centaurea humilis )
- Weak Combed knapweed (Centaurea semipectinata )
- Brandenburg knapweed (Centaurea brandenburgica )
- Ordinary meadow knapweed (Centaurea vulgaris)
- Deceptive knapweed (Centaurea decipiens )
- Kleinfedrige knapweed (Centaurea microptilon )
- Western knapweed (Centaurea diluvialis )
- Late Blooming Cornflower (Centaurea serotina )
Use
The meadow knapweed endures twice mowing, if the first cut is not made by early July. Due to their high content in tannins, it is, however, a bad feed plant.