Excerpts from Jim Conrad's
Naturalist Newsletter

from the March 2, 2009 Newsletter, issued from near Natchez, Mississippi:

When I was a kid on the Kentucky farm cocklebur and foxtail grass were the two main weeds plaguing our soybean fields. On the banks of levees beside St. Catherine Creek NWR's flooded fields I saw that cockleburs continue to be a problem today, as shown below:


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:

Common Cocklebur, XANTHIUM STRUMARIUM, fruit

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 March 10, 2013 Newsletter issued from the valley of the Dry Frio River in northern Uvalde County, southwestern Texas, on the southern border of the Edwards Plateau, USA

Along the banks of the little Dry Frio River behind the cabin Common Cockleburs with their leafless, dead stems still bearing burs produced last season can be seen, as shown below:

Common Cocklebur, XANTHIUM STRUMARIUM, plant in winter

What draws my attention to these plants is that they are so tall -- about six feet (1.8m) and that their stems look and feel as woody as a small tree's. Cockleburs are annuals, though, and all the literature describes them as herbaceous.

The burs also are interesting because they're different from those I'm familiar with back in Kentucky and Mississippi. You can compare the bur illustrated in the above section with one from a plant along the Dry Frio shown below:

Common Cocklebur, XANTHIUM STRUMARIUM, bur showing spines with spiny bases

The main difference is that the Dry Frio burs' long, hooked spines themselves bear tiny, stiff spines at their bases -- spines on spines -- while the Mississippi burs' spines have smooth, spineless bases.

Back in the 60s when I was learning my plants in Kentucky I had a hard time identifying our local cockleburs to species level because our plants didn't match the descriptions in the technical keys I was using, and there were many species to choose from. Nowadays it's a lot simpler, since nearly all the "species" I wrestled with back in Kentucky now have been lumped into one very variable species, the Common Cocklebur, XANTHIUM STRUMARIUM. The online "Integrated Taxonomic Information System" at http://www.itis.gov lists 38 previously recognized species and varieties now considered to be mere variations of Xanthium strumarium. Now the entire genus Xanthium is thought to comprise only two or three species.

So, generations of botanists huffed and puffed and worked themselves into a sweat trying to figure out cocklebur taxonomy. There were great debates and mighty pronouncements but, in the end, now that we can look at the genes, we see that all those variations on the cocklebur theme never could have been properly assigned to any of the taxonomic pigeonholes thought up for the plant -- except for the one labeled "it's all the same."

from the September 21, 2006 Newsletter issued from Polly's Bend, Garrard County, in Kentucky's Bluegrass Region, USA:

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...