Spotted Knapweed

Growth Form:  Forb

General:   Biennial herb; first year plants form low-growing rosette of leaves (may remain in rosette stage for >1 yr on extreme sites), second year plants form one to 20 hairy, tall stems. Blooms from early July to September.

Flowers:   Flowers thistle-like, pink to purple, base surrounded by stiff, black-tipped bracts (gives flower "spotted" appearance).

Fruits and Seeds:   Seeds thistle-like, wind blown.

Leaves:   Leaves alternate, dark green, as wide as long, rounded (young leaves may be longer than wide).

Stems or Branches:   Second year produces from one to 20 hairy, up to 1 meter high stems

Threatens:   Savannas and prairies, especially on sandy or gravelly (dry) soils and often grows in disturbed sites, such as roadways, trails, old fields.

Look-Alikes:   None locally.

Distribution:   Native to Europe and W Asia. Widespread in Canada and U.S.

Other Links:  

http://www.invasivespeciesinfo.gov/plants/spotknapweed.shtml
http://www.nps.gov/plants/ALIEN/fact/cebi1.htm
http://www.invasive.org/eastern/biocontrol/13Knapweed.html
http://www.dnr.state.mn.us/invasives/terrestrialplants/herbaceous/spottedknapweed.html