abc .
Plants of fields, roadsides, open disturbed areas.  Flowers July to September.  Not native.  Considered a hybrid of C. jacea and C. nigra.

Perennial.  Stems are 1 or more per plant; sparsely to somewhat more densely pubescent with matted or cobwebby hairs; often branching from below midstem.  Typical height is 2 to 3+ feet.

The overall inflorescence is open, with numerous widely spreading to ascending branches, each branch bearing a small number of flower heads, clustered toward branch tips.

Flower heads are discoid, or more often pseudo-radiate (i.e., not truly "radiate" or with true ray florets).  Involucres are 15-18 mm high, often taller than wide.  Florets are 40-100+.

Enlarged peripheral florets, if present, are neuter, infertile, falsely appearing as rays, with pink/magenta corollas.  Central florets are bisexual and fertile; smaller than peripheral florets, corollas pink or white, tubular, apically with 5 slender, spreading lobes.  

Appendages of involucral bracts are dry, thin, rounded or nearly triangular in shape, light brown to dark brown; the outer more often with some comb-shaped fringes along the edges; the middle deeply cut or toothed;  the innermost (i.e., toward the top of the involucre) may be rounded or truncated and irregularly cut along the top margin.  In other words, appendages of involucral bracts are intermediate between those of C. jacea and C. nigra

Basal and lower stem leaves, sometimes present at flowering, are often irregularly lobed and/or toothed.  Upper leaves are oblanceolate, lanceolate or elliptic, irregularly lobed and/or toothed, becoming smaller and untoothed/unlobed upwards and on branches.  Leaves are glabrate or thinly pubescent with matted or cobwebby hairs.

Cypselae are tan.  The pappus is of minute (0.5-1 mm) bristles (sometimes lacking or falling off).

.

Selected references:  Keil and Ochsmann (2006)Haines (2011).

.

.

Similar species:  other species in the genus Centaurea.

 

.

.

.

.

..


Images and text copyright  botphoto.com  and Arieh Tal, 1990 to 2016.  All rights reserved.  ( Terms of use )
.