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.