Vascular Plants of Wisconsin

Arctium minus Bernh.
burdock
Family:
Asteraceae
native: no
type: herbaceous biennial

plant basal leaves flower head fruiting fruit seeds
 

The flowering stems of Arctium minor may be 1.5 meters tall and the basal and lower leaves may be as large as 1/2 meter in length and nearly as wide. It is a biennial species, so during the first year in which a new seedling becomes established, only the large basal leaves are produced. During the second year the plant sends up a tall flowering stem. After flowering and producing seeds, the plant dies.

Arctium minus is a large weed introduced to North America from Europe and now widely naturalized throughout the U.S. The "empty" counties on the Wisconsin distribution map probably indicate a reluctance of people to collect scientific vouchers of this large weed, rather than true absence. In Wisconsin it usually begins to flower in July and continues late into the summer. The fruiting stems remain upright throughout the next winter. The hooked tips on the bracts of fruiting heads readily attach the fruits to the hair (or clothing, etc) of passing animals, assisting in the dispersal of seeds. The ability of the fruits to stick tightly to fur or clothes is said to have been the inspiration for the invention of "velcro".

 

 


known distribution based on vouchers

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