Xanthium strumarium (Cocklebur) - photos and description
Photo taken on July 7th, male flower heads visible.
Photo taken July 7th.
Pistillate flower heads have two flowers surrounded by a spiny
involucre.
Photo taken August 14th, female flowers have developed into fruit
(burs).
Spines with hooked tips.
General: Annual plant with a decumbent, much-branched growth habit. Stems and leaves rough hairy.
Flowers: Male flowers in globose flower heads. Female flower heads ending in two beaks each containing 1 flower, the flower having a divided style, the spiny involucre of the pistillate flower head developing into burs. We measured male flowers at 1.5 mm long, and the styles of female flowers at 2 mm long. Male flower heads were measured at 6 mm diameter, burs measured at 15 mm long.
Leaves: Leaves alternate, broadly triangular with a wavy margin. The leaf highlighted in the photo above was measured at 7 cm long by 8 cm wide.
Height: Height listed in Budd's Flora to 60 cm. We measured plants to 29 cm tall.
Habitat: Roadsides, waste ground, fields, low saline ground.
Abundance: Common.
Origin: Native.
When and where photographed: Photos taken July 6th, 7th, and August 14th on waste ground, University of Regina, in our home city of Regina, SK.