knapweed

(napwēd′)

noun

any of several weedy plants (genus Centaurea) of the composite family; esp., a hardy perennial (C. nigra) with heads of rose-purple flowers

Origin: earlier knopweed: see knop & weed

See knapweed in American Heritage Dictionary 4

noun
Any of various thistles of the genus Centaurea, having variously colored flowers grouped in a head with a spiny involucre.

Origin:

Origin: Middle English knopwed

Origin: : knop, knob; see knop

Origin: + wed, weed; see weed1

.

Learn more about knapweed

knapweed

link/cite print suggestion box