Cocklebur (Xanthium strumarium)

A summer annual that produces a conspicuous prickly "cocklebur" fruit and ranges from 1/2 to 6-1/2 feet in height. Common cocklebur is found throughout the United States and is primarily a weed of agronomic and horticultural crops, nurseries and occasionally pastures. Seedlings have cotyledons that are linear to oblong in outline, waxy, smooth, fleshy and thick. The first true leaves are opposite, while all subsequent leaves are alternate. Mature leaves are triangular to ovate in outline, have stiff hairs, and are 2 to 6 inches long. Leaves are irregularly lobed and occur on long petioles. Flowers are inconspicuous and greenish in color.

IPM1007, revised June 2007