Plant Name

Scientific Name: Xanthium strumarium

Common Names: Rough Cocklebur, Common Cockleburr

Plant Characteristics

Duration: Annual

Growth Habit: Herb/Forb

Arizona Native Status: Native

Habitat: Desert, Upland, Riparian. This weed grows in desert washes, drainage ditches, and at field edges.

Flower Color: Inconspicuous (greenish)

Flowering Season: Summer, Fall

Height: To 5 feet (1.5 m) tall in favorable locations

Description: The male flower heads are found at the stem tips, while the female flower heads are found in the leaf axils. The female flowers are followed by spiny, sometimes glandular, up to 1 1/2 inch (3.8 cm) long, cylindrical to barrel-shaped, green drying to red-brown burs. The dry burs are covered with stout, sharp, hooked spines that allow them to easily adhere to clothing or fur. The leaves have a rough, scratchy surface texture and are dull green, broadly heart-shaped, and coarsely toothed.

Special Characteristics

Allergenic – The pollen is a moderate allergen. Also, contact with the rough, glandular foliage can cause allergic contact dermatitis in susceptible persons.

Poisonous – The seeds and cotyledons are dangerously poisonous and contain the highly toxic glycoside carboxyatractyloside.

Classification

Kingdom: Plantae – Plants
Subkingdom: Tracheobionta – Vascular plants
Superdivision: Spermatophyta – Seed plants
Division: Magnoliophyta – Flowering plants
Class: Magnoliopsida – Dicotyledons
Subclass: Asteridae
Order: Asterales
Family: Asteraceae – Aster family
Genus: Xanthium L. – cocklebur
Species: Xanthium strumarium L. – rough cocklebur

More About This Plant

Arizona County Distribution Map
Rough Cockleburr (Xanthium strumarium) – The Firefly Forest