Spotted Knapweed
Centaurea maculosa Lam.
Family: Asteraceae, Aster
Genus: Centaurea
Synonyms: Centaurea biebersteinii
Other names: cornflower
Nomenclature: maculosa = spotted
Nativity / Invasiveness: noxious weed in Montana
No edibility data
No medicinal data

General: plant 30-150 cm tall. Growth habit: erect, biennial or short-lived perennial, tending to be taprooted, rough-hairy, freely branched, lacking spines.

Leaves: alternate, pinnately cut into thin, linear, narrow lobes, or the reduced upper ones entire, with thin and loose, soon falling off woolly hairs, also sparsely rough short-hairy. Leaves are obscurely to evidently glandular-dotted.

Flowerheads: pink-purple or rarely white, about 2.5 cm wide, with disk florets only, the marginal florets enlarged. Many heads on long stalks in open, branching clusters. Involucre urn-shaped, 10-13 mm high, its bracts in several rows, lined lengthwise, the middle and outer ones with short, dark, stiffly fringed tips. June-October.

Fruits: achenes, with pappus of white, hair-like bristles, up to 2 mm long, or rarely absent.


Locally very common in fields, roadsides, and waste areas in w. c. and s. parts of MT. Classified as noxious weed. Native of Europe, now widely established in the U.S.
Advertising Disclosure: Montana Plant Life may be compensated in exchange for featured placement of certain sponsored products and services, or visitors clicking on links posted on this website.
Copyright ©