Clotbur - Large Cocklebur - Woolgarie Bur
Xanthium strumarium Linnaeus; Var. canadense
Sunflower (Daisy) (Asteraceae) Family
Cocklebur produces two kinds of flowers. One is in short terminal branches and produces only pollen. The other is a cluster in the leaf axil and produces seed.
The fruit is a small, hard, 2-chambered bur, oval in shape and about 3/4 inch long. It is covered with strong, hooked spines. The seedling is the plants most dangerous stage and is very different from the mature plant. It consists of a slender, straight whitish green stem 1 to 3 inches tall. The seed capsules mature in late summer. This plant reproduces by seed only.
Pigs rooting and grazing in cocklebur infested places are the most often poisoned domestic species. Poisoning also affects cattle, sheep, horses, and fowl. The plant is most hazardous at the seedling stage because of its toxicity as well as palatability. Ingestion of young seedlings may result in various signs of toxicosis. The seeds are poisonous, but are seldom eaten because of their spiny capsule. Occasionally the eating of the ripe spiny capsules is said to result in intestinal obstruction. Mature plants, however, are seldom eaten, perhaps because of their bitterness and rough texture.
The Zuni people use the canadense variety for multiple purposes. The chewed seeds are rubbed onto the body before the cactus ceremony to protect it from spines. A compound poultice of seeds is applied to wounds or used to remove splinters. The seeds are also ground, mixed with cornmeal, made into cakes, and steamed for food.