Centaurea dubia  (C. nigrescens) short-fringed knapweed Asteraceae CEDU*; Bx, pb, vc; R (DeCandido 2001);

   

Centaurea dubia.Arthur Haines.Copyright © 2014.New England Wild Flower Society.gobotany.newenglandwild.org

Centaurea dubia.Arthur Haines.Copyright © 2014.New England Wild Flower Society.gobotany.newenglandwild.org. (Accessed 11/2014).

Centaurea dubia  is a perennial herb, 20-80 cm tall, branched, finely hairy or webby when young. 

Leaves alternate, stem leaves sessile, lance-shaped, entire or toothed, basal leaves stalked, sometimes lobed, 1.5-4 cm wide, much smaller above. 

Flowers pale purple, all discoid, marginal flowers, enlarged, ray-like, with long, narrow petal lobes; flower heads terminal on branches, bracteate base 1.1-1.8 cm high, urn-shaped, mostly taller than wide, bract tips with blackish, regularly pinnate appendage 1-3 mm long, having a spider-like or feather-like appearance. 

Fruit dry 1-seeded achenes without plume but inner surface of flower head base densely short-bristly, blooming and fruiting June-Sept. 

Wetland status: UPL. 

Frequency in NYC: Very infrequent. 

Origin: Europe. 

Habitat: Along weedy edges, roadsides, meadows.