There were miles and miles of levees and miles and miles of cockleburs at the water's edge. Of course the plants in the picture are dead, for cockleburs are annual plants. However, dead cockleburs retain stiff stems that hold the spiny fruits up well into spring, the idea being that the fruits will latch onto a passing animal's fur and be carried to a new location. You can see how well equipped a bur is for that job below:

Cocklebur taxonomy is a matter of debate, some specialists recognizing only three species in the genus and others many more. The species pictured here is surely the Common Cocklebur, XANTHIUM STRUMARIUM, native to North America despite its aggressive weediness here.

from the September 21, 2006 Newsletter:
COCKLEBUR
I read that young cocklebur plants in the two-leaf stage are poisonous enough to kill pigs and other animals. As often is the case, what's poisonous in one instance can be medicinal in another. Cockleburs are still used in traditional Chinese medicine.

At http://www.acupuncturetoday.com/herbcentral/xanthium.html where they call cocklebur by its genus name Xanthium I read:

"... xanthium is associated with the Lung meridian, and is considered to have sweet, bitter and warm properties. It is used to dispel wind and damp, and is one of the most important herbs used for sinus congestion, chronic nasal obstructions and discharges, and respiratory allergies."

The spiny fruit is what's used. The above site also informs us "some evidence suggests the toxicity can be removed by washing the fruit in water, subjecting it to high heat, or stir-frying it."

Stir-fried cockleburs...