Asteraceae

Centaurea x moncktonii

Common Names: Black knapweed

Plant Form: Upright perennial herb. Size: Usually under 1 m tall. Stem: Ribbed, roughly hairy. Leaves: Alternate on stems up to 8 cm long along main stem, undivided, narrow or widest towards base, weakly toothed, sessile. At base of plant clumped, sometimes lobed, up to 25 cm long. Flowers: Solitary cornflower-like flowerheads with purple florets 15-20 mm long. Brown bracts surround the flower giving a pine-cone like appearance. Fruit and Seeds: 2-3 mm long, pale brown to grey, with reduced parachuting hairs only 1 mm long or missing. Habitat: Roadsides, disturbed sites, pastures. Distinguishing Features: Distinguished from Creeping knapweed (Rhaponticum repens) by having dark brown or black tip on bracts, and Spotted knapweed (Centaurea stoebe subsp. micranthos) by generally having less deeply lobed leaves.