Etymology: palustre = of marshes
Plants: erect, biennial, 1' - 6 1/2' tall forb; stems spiny-winged
Flowers: head 3/4" wide with purple disk flowers, bracts (phyllaries) tips not spiny; inflorescence of usually many clustered heads; blooms June-July
Fruits: dry seed on fluffy, feathery-divided pappus usually less than 1/3" long
Habitat: we to moist; woods, roadsides
Invasiveness: Prohibited/Restricted Invasive - Eradicate!
Conservation Status: Introduced - naturalized; ecologically invasive

Stout, white-woolly stemmed perennials 3-7 dm tall. Leaves lanceolate to oblanceolate, tomentose beneath, more thinly so above, shallowly lobed to undulate-pinnatifid, the lobes broadly triangular, usually more than 7 mm wide at base, ending in a short, firm spine, the lower midrib conspicuous.Heads solitary to several with pinkpurple corollas; involucre 3-3.5 cm high; bracts 2-4 mm wide, glutinous-ridged, woolly on the margins, the outer obtuse with a flattened broad-based spine, the innermost attenuate int o erose tips. Achenes with very narrow yellow apical band.

Native of the western Great Plains, rarely adventive eastward, in Wisconsin local, very sporadic ... Flowering in June and July; fruiting in August.

Johnson, M.E. and H.H. Iltis. 1963. Preliminary reports on the flora of Wisconsin: No. 48. Compositae Family. Wisconsin Academy of Sciences, Arts & Letters. 52:255-342.

Often confused with Cirsium fiodmanii, but with more shallowly and wider lobed leaves, the middle cauline half-clasping, larger heads, longer florets and anthers, and wider involucral bracts.

Johnson, M.E. and H.H. Iltis. 1963. Preliminary reports on the flora of Wisconsin: No. 48. Compositae Family. Wisconsin Academy of Sciences, Arts & Letters. 52:255-342.

Other Treatments:  

Flora of North America

Michigan Flora

USDA Plants

Wetland Plants of WI

 
Additional Resources:  

GLANSIS

InvasivePlantAtlas.org

USDA-Forest Service

WI DNR