Family: Asteraceae,
Aster or Composite
Genus: Centaurea
Description
Plant height: 30-150 cm tall.
Growth habit:
erect, biennial or short-lived perennial,
tending to be taprooted.
Stems:
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.
Flowering time: June-October.
 Fruits: achenes, with pappus of white, hair-like bristles,
up to 2 mm long, or rarely absent.
Distribution
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. |
|
|
|
(click on image for full size)
|
