Common Cocklebur

Cocklebur, rough cocklebur

Common Cocklebur is a course summer annual broadleaf plant. It can grow about 2-4 feet tall and little branched, except for short side stems appearing from the leaf axils. Leaves of this many branched annual are alternate, hairy, rough-textured, somewhat heart shaped, toothed and lobed. Flowers are inconspicuous with male flowers in terminal spikes and female flowers in clusters in the leaf axils. The fruit is hard, oval and prickly burs about ¾ inches long containing two seeds. The seeds germinate best after being soaked by water. 

Blooming of Common cocklebur usually occurs late summer or early fall. Pollination is by wind and there is no floral scent. Each female flower within the bur-like bract produces one oblong seed. The root system consists of a taproot that is stout and rather woody. 

Common Cocklebur can be found on right-of-ways, ditches, valley bottom lands, pastures, cultivated crop fields, orchards, riparian areas, wetlands and disturbed areas. 

Herbicides that control Common cocklebur are glyphosate, Dicamba, 2,4-D, and Tordon. For more information on herbicides and mixing instructions read the labels or contact the Weed and Pest office. Cutting/mowing the plant before it flowers is also effective. 

All classes of livestock can be poisoned following ingestion of seedlings in the cotyledonary stage. The poisonous substance is hydroquinone. The seeds are the most poisonous but are usually not eaten because of the protection of the burs. The burs can also cause significant economic losses when in sheeps wool.