Cirsium discolor (Muhl. ex Willd.) Spreng. - Field Thistle


 

|  back  | forward |

Cirsium discolor - (image 1 of 4)

 

Taxonomy

Family: Asteraceae

Habitat

Fields, meadows, roadsides, open woods, mostly in disturbed areas.

Associates

 

Distribution

Southern Quebec and Ontario to MN and adjacent Manitoba, south to NC, MS, LA, and KS.

Morphology

Fibrous-rooted perennial or biennial; stem 1-2 m, openly branched, spreading hirsute to subglabrate, sometimes slightly tomentose in the inflorescence; leaves deeply pinnatifid, firm, spiny, broadly oblanceolate to obovate or elliptic, densely white-tomentose beneath, scabrous-hirsute to subglabrous above; heads several or numerous on leafy peduncles; involucre rather broad based; middle and outer bracts tipped with a spine 2-5 mm; inner bracts attenuate or often with a scarious, slightly dilated and erose tip; flowers pink-purple; achenes 4.5-6 mm.

Notes

Flowers July to October

Wetland indicator: UPL

Grows to about a meter in height in sandy soil but can be much taller in rich soil. Like other native thistles this species is great for attracting pollinators. Cirsium altissimum is similar but often taller with more narrower involucres and leaves toothed or shallowly lobed but not deeply pinnatifid.

References

Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Second Ed.
The New York Botanical Garden. Bronx, NY

 


Home

 

 Michael Hough 2018