Family: Asteraceae
Flodman's thistle, prairie thistle
[Carduus flodmanii Rydb., more...]
Emmet J. Judziewicz
Emmet J. Judziewicz
Etymology: Flodmanii = named for J.H. Flodman who discovered the plant.
Plants: erect, perennial, 12"-32" tall forb spread by creeping roots which become taproots on the new plants; usually a single stem covered with dense, whitish fuzz
Leaves: usually deeply pinnately-divided with long triangular lobes, underside with whitish fuzz
Flowers: head 1" wide with a rounded base and purple disk flowers; inflorescence with one to a few clustered heads; blooms June-Sept.
Fruits: dry seed with a yellow band on fluffy, feathery-divided pappus
Habitat: moist; poorly-drained areas mostly along railroads
Conservation Status: Introduced - adventive
Plants: erect, perennial, 12"-32" tall forb spread by creeping roots which become taproots on the new plants; usually a single stem covered with dense, whitish fuzz
Leaves: usually deeply pinnately-divided with long triangular lobes, underside with whitish fuzz
Flowers: head 1" wide with a rounded base and purple disk flowers; inflorescence with one to a few clustered heads; blooms June-Sept.
Fruits: dry seed with a yellow band on fluffy, feathery-divided pappus
Habitat: moist; poorly-drained areas mostly along railroads
Conservation Status: Introduced - adventive
Slender woolly-stemmed perennial 3-6 (-9) dm tall, spreading prolifically by root sprouts. Leaves lanceolate, densely permanently white-woolly beneath, less so and often glabrate above, subentire to deeply undulate-pinnatifid (then very spiny), the lobes narrowly lanceolate to triangular, usually less than 7 mm wide at the base (rarely wider in rosette leaves), ending in firm yellow spines. Heads with bright purple corollas, the involucre 2-2.7 cm high, the narrow bracts to 2.5 mm wide, glutinous-ridged and fiocculose, the outer abruptly contracted, the apical spines divergent, the inner acuminate. Achenes 2.5-3.5 mm long, light brown with a distinct yellow apical band more than 1/2 mm wide.
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 the Great Plains, recently introduced in Wisconsin on sandy roadsides, along railroads, and disturbed areas, and rarely established in native prairie [Shinne rs 1173, Dane Co. (WIS)]. Flowering from late June to early October; fruiting from August through October. This species is very similar to the more robust C. undulatum. A careful analysis of their differences may be found in Frankton and Moore (1961).
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:
Emmet J. Judziewicz
Derek Anderson
