Cirsium discolor X C. muticum (Muhl. ex Willd.) Spreng.   (redirected from: Cirsium muticum X C. discolor)
Family: Asteraceae
[Cirsium muticum X C. discolor Michx.]
Cirsium discolor X C. muticum image
Morphologically intermediate between the parental species. Stem slender, slightly ridged, subglabrous, branching above or simple. Leaves lanceolate to oblanceolate, pinnatifid, the primary lobes lanceolate to cuneate, usually with opposite cuneate to lanceolate secondary lobes, all with short, firm spines, the pubescence beneath sparsely cobwebby, sub-glabrous above. Heads lavender, intermediate between the parental colors. Involucre 22- 27 mm high, the outer bracts glutinous, short, obtuse, terminated by spines only 1.2-1. 5 mm long, the inner ones elongate-acuminate. Achenes brown, 4-4.5 mm long

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.

The hybrids are intermediate between the parents in leaf pubescence, flower color, and length of involucral bract spines. Almost all achenes in the Wisconsin collections are aborted, indicating hybridity. Though their overall ranges overlap, the parents are ecologically isolated, C. muticum occurring in wet prairies, C. discolor in mesic or dry prairi es. Ownbey (1951) showed that in Minnesota the parental species (and with them numerous hybrids) grow sympatrically only where the habitat was disturbed by roadbuilding operations. The Wisconsin hybrids cited below give no indication of any association with the parental forms, though this must be assumed: Dane Co.: Dry hillside, C. & NW. RR, 4 mi. SW. of Madison, Sept. 24, 1939 [fl], Shinners 1173 (WIS, WISM). La Crosse Co.: Moist acid meadow, Sept. 7, 1956 [fr], Hartley 3114 (WIS). Marquette Co.: Germania, Hartwell s.n. (WIS).

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.

Cirsium discolor X C. muticum image
Cirsium discolor X C. muticum image
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