Knapweed (2)

Spotted Knapweed
Centaurea maculosa

Family: Sunflower (Asteraceae)
AKA:
Photo taken on: August 15, 2007
Location: Taylor Canyon, GV, CO
Life Zones: Plains to foothill
Habitat: Disturbed soil, roadsides

Grows to 4ft with deeply cut hairy leaves with no spines. Bracts have a hairy black tip making it look "spotted".

NOXIOUS

Russian Knapweed
Acroptilon repens (Centaurea repens)

Family: Sunflower (Asteraceae)
AKA: Hardheads
Photo taken on: July 25, 2014
Location: SR 285 S of Tres Piedras, NM
Life Zones: Plains to montane
Habitat: Roadsides, ditch banks, pastures, waste places

Grows in a bush 1ft to 3ft high with stiff branches. Flowers are ½" to ¾" across and thistle-like, white to lavender. Bracts are smooth with rounded tips, green and cobwebby. It is toxic to horses.

Flora of North America reference.

NOXIOUS