Knapweed, Blackotanical: Centaurea nigra (LINN.)
Family: N.O. Compositae
Centaurea nigra, the Black Knapweed, is a perennial, with an unwinged, erect stem, 6 inches to 3 feet high, generally freely branched in the upper part. The leaves are very variable, both in breadth and degrees of division, the upper ones narrow and generally with entire margins, but the lower ones lobed, or at any rate with some coarse teeth. The whole plant is dull green, rather rough with small hairs, the stems, like the preceding species, very tough. The flowers are without the spreading outer rays of the Greater Knapweed, the florets being all tubular, which makes the black fringes to the bracts of the involucre most noticeable, hence the name of the species. The florets are of a less bright purple in colour.