Squarrose Knapweed

Squarrose Knapweed

Centaurea virgata Lam.

(formerly Centaurea squarrosa Willd.)

Asteraceae (Sunflower Family)

▲ ▼ mature, flowering plants

▲ ▼ closer view of flowers

▲ ▼ flowering stems

▲ ▼ closer view of inflorescences/flowers

Centaurea virgata Lam. (formerly Centaura squarrosa Willd.), Squarrose Knapweed: (Bayer Code: CENSQ; US Code CEVI)

Simple perennial with stout rootstock native to Asia
Produces several, much-branched stems with rough hairs
Lower leaves are pinnately compound, gray-green and rough-textured, but upper leaves lanceolate to linear and unlobed
Inflorescences are flower heads with 4-8 pinkish ray flowers
Bracts below the inflorescence are light green with tan, comb-like spines along their edges, and bract tips point outward, away from the base of the head
Bract arrangement is similar to diffuse knapweed (Centaurea diffusa), except bract tips hug the inflorescence base, and diffuse knapweed flowers are usually white, flowering stem leaves may continue as pinnately lobed, and diffuse knapweed is a biennial or short-lived perennial

(Posted January 23, 2019)