Carduus acanthoides
Family: Asteraceae
plumeless thistle,  more...
Carduus acanthoides image
Clifford Orsted  

Etymology
: Acanthoides = resembing a spine or thorn
Plants
: erect, biennial, 1'-4' tall forb; stems tough, spiny-winged
Leaves
: deeply lobed to pinnately-divided
Flowers
: head 1/2"-1" wide with pink disk flowers, bracts (phyllaries) spiny; inflorescence an erect, usually a solitary head or in clusters at the ends of the branches and (if present) on a long, winged stalk; blooms July-Oct.
Fruits
: 4-angled, dry seed with a fluffy, but not feathery pappus
Habitat
: disturbed sites, roadsides
Invasiveness
: Restricted Invasive - Eradicate!
Conservation Status
: Introduced - naturalized; ecologically invasive
Very spiny annuals or biennials, usually less than 1 m tall. Leaves lanceolate, deeply undulate-pinnatifid, the acuminate lobes armed with stiff yellowish spines, glabrous to sparsely pilose beneath, the bases decurrent, farming several conspicuous spiny wings along the entire stem. Heads clustered; involucres 1.5-1.7 cm high, the bracts narrow, erect, the corollas bright rose-purple. Achenes 2.5-2.7 mm long, tannish and shallowly furrowed. 2n=22 (Poddubnaja 1931, ex Darlington 1955).

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.

Native of Europe and Southern Russia (Hegi), very recently introduced and only locally abundant in south-central Wisconsin where becoming a serious pest, mainly in valley bottom pastures and grazed calcareous hillsides in Iowa and Green Co's., on railroads and prairies in Dane Co., and near Marquette [Green Lake Co.: Ugent s.n. (WIS)] in open oak-maple woods, on thin soil at base of granite outcrops, with Oenothera biennis, Cemstrus scandens, Circaea quadrisulcata, and Geum canadense! Flowering from mid-July to early August; fruiting to September.

Resembling Cirsium vulgare and C. palustre in the spiny stem wings, but differing from C. vulgare by less spiny involucres and the capillary pappus, and from C. palustre by larger, less clustered heads and the capillary pappus.

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.

Carduus acanthoides image
Emmet J. Judziewicz  
Carduus acanthoides image
Kenneth J. Sytsma  
Carduus acanthoides image
Botanical Illustration  
Carduus acanthoides image
Carduus acanthoides image
Kenneth J. Sytsma  
Carduus acanthoides image
Carduus acanthoides image
Hugh H. Iltis  
Carduus acanthoides image
Robert Bierman  
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
Carduus acanthoides image
   View Genus       View Specimen Records