GROWTH HABIT: Common cocklebur, an annual, 2 to 4 feet tall.LEAVES: Leaves alternate, triangular or heart-shaped, rough on both sides and long petioled.
STEMS: Stem erect, branched, ridged, spotted and very rough.
FLOWER: Flowers are small, in axils of upper leaves; male and female flowers are separate. Fruits are 1 inch long, woody, with hooked prickles and two curved spines at the tip and two seeds. Flowering may occur from July to September.
SEEDS: Dark brown seeds are flattened and pointed tips. Both seeds and seedlings contain a substance toxic to livestock.OTHER: Common cocklebur is native to North America, but is now worldwide in distribution. Several other species are present in the West. Cocklebur is common in cultivate fields, abandoned land, run-down pastures, road ditches and waste areas. The burs are irritating both to humans and animals, and when found in wool, depreciates its value.