Family: Asteraceae
common burdock, lesser burdock
[Arctium minus f. laciniatum (Hill.) Bernh., more... ]
Etymology: minus = less
Plants: erect, biennial, 1 1/2'-5' tall forb
Leaves: alternate, large, heart-shaped base, on stalks getting shorter toward the top, lower stalks mostly hollow
Flowers: head 3/4"-1" wide with pink to purplish disk flowers, bracts (phyllaries) with hooks curving inward; inflorescence clusters of short stalked or stalkless heads; blooms July-Oct.
Fruits: round, bristly, 1/2" clinging bur (inspiration for Velcro)
Habitat: roadsides, disturbed sites
Invasiveness: Invasive - Eradicate!
Conservation Status: Introduced - naturalized; ecologically invasive
Coarse robust biennials, 2 m tall or more, branched above. Basal rosette leaves large, broadly ovate-cordate, cottony and frequently atomif erous to glabrate beneath, glabrous to floccose above, entire. Heads numerous, crowded on mostly very short peduncles; corolla rose to purple. Involucre 1-1.6 cm high, (1.5-) 2-2.5 cm. wide (from tip to tip of bracts); bracts glabrous or arachnoid, linear, rigid, with hooked tips, usually exceeding the corollas. Achenes 4.5-5 mm long, irregularly rugulose. 2n=32 (Wulff 1937, 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 to temperate Europe and east to the Caucasus, naturalized in Wisconsin as a weed indicative of nitrogenous soils (Curtis 1959), common in roadside communities, abandoned fields, heavily grazed pasture, and often along cow paths and other disturbed habitats where relatively free from competition. Flowering from July through September (-November), fruiting from August through November.
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.