Sunflower Family

Xanthium strumarium L.

(X. saccharatum Wallr.)

A fairly common weed during the fall season in Cochise County is the common cocklebur, which also possesses poisonous properties.

Common cocklebur produces the unpopular burs which badly tangle the manes, tails, wool, and hair of many types of animals, including dogs. Its burs may be spray painted and sold in gift and tourist shops as "porcupine eggs."

Common cocklebur, a stout, bushy, 2 to 3 foot high annual, reproduces by seed. Its triangular leaves are long stalked and may be up to 14 inches long and 8 inches in width. The flowering branches are short and develop at leaf axils (along the main stems). The top round clusters form the male flowers; the highly conspicuous, football-shaped burs at the bottom are actually the two female flowers, and are covered by approximately 400 stiff spines. Each spiny bur contains two seeds, perhaps 1/2 inch long; and they will remain fertile for many years to come.

This plant grows in the moist soils of cultivated fields, pastures, flat land, and roadsides, even around water holes. It flowers from June to October, and grows at elevations up to 6,000 feet in altitude.

Hogs are particularly susceptible to poisoning by the seeds and the seedling plants of cockleburs. It should be noted that seedlings will also poison chickens, sheep, cattle, and horses. Usually animals don't eat the seeds for obvious reasons. Fortunately, as the seedling plant grows, it's potential for causing toxicity decreases at a rapid rate.

Poisoning symptoms include the following: weakness, unsteady gait, rapid breathing, subnormal temperature, rapid but weak pulse, convulsions, and vomiting. Death due to fatal poisoning occurs from 12 to 24 hours after the onset of the symptoms.

Note: Spiny Cocklebur - Xanthium spinosum L.

This species of cocklebur, with its short and narrow-pointed leaves, does not resemble the common cocklebur. This plant has 3-forked spines at the base of each leaf (leaves tend to be silvery-white on the underside). The burs are short spined, perhaps 1/3 to 1/2 inch in length. This cocklebur is more common in Santa Cruz County.