Rural folk know all about cockleburs. The pesky weed sprouts in barnyards, vegetable gardens and pastures. We also know that it is hard to eradicate once it has a foothold. Mowing only stimulates regrowth and the seeds continue to mature long after a plant is dug or pulled out from the root. This plant is so tenacious that the two seeds that are contained in each spiny capsule germinate in different years. One behaves as a normal annual seed, germinating in the next spring, but the second seed contains a germination inhibitor that keeps it from sprouting for at least two years.

Xanthium strumarium is a North American native, but has spread throughout the world and attained pest status in many countries. This plant grows well in many soils, including poor soil and thrives in full to partial sun. Edges of agricultural fields are a prime area to find them and once established, a perennial resident in those fields. It even withstands flooding for up to 6 to 8 weeks. This crafty little plant actually produces long rootlets along the stem that float on the flood waters and provide oxygen for the cocklebur's survival. The seeds can float for up to 30 days as well. It should have been cast in the Star Wars franchise because: "The Force is strong in this one."

The spiny seed pods mature in the fall and are easily detached from the parent plant by animals walking or grazing in the vicinity. I had horses growing up and they often collected cockleburs in their manes and tails. Since their heads were low as they grazed on grass, they actually ended up with more in their manes than their back ends and I was constantly working on them each fall. Sometimes the only way to remove them was to cut them out. I didn't realize it at the time, but these plants are toxic for most grazing animals. The horses must have realized this since they avoided eating them. Deer will browse older plants and the seeds are consumed by squirrels and birds. The cocklebur was a main food source of the now extinct Carolina Parakeet. Apparently the younger the plant, the more toxic it is. The poison substance is called carboxyatratyloside and is most concentrated in the cotyledons (seed leaves) when the plant germinates. Mature leaves contain smaller amounts and were even eaten by humans in times of famine. They can safely be consumed if boiled through two changes of water, much like polk salad. Antidotes consist of milk, oils, and fats like lard, but it isn't wise to experiment with this plant in the kitchen.

Early peoples had a number of uses for this plant. The leaves produce a yellow dye and the crushed seeds were mixed with fats to create a blue toned body paint. The Zuni crushed the seeds and rubbed them over their bodies during their Cactus Ceremony, while the Lakota and Iroquois believed the plant contained mystical properties. They also used the ground seeds as a flour extender, mixing it with cornmeal that they made into cakes. The seeds contain about 38% protein and 39% fat, so they provided a significant source of nutrition for these early peoples.


There are some medical uses as well. The crushed plants contain anti-bacterial and anti-fungal properties and were applied to open sores in the form of poultices, so they might be an emergency source of first-aid for hikers and backwoods enthusiasts. The root was boiled and used as a treatment for malaria and high fevers. One interesting use was as a prehistoric antiperspirant. The crushed plants were rubbed over the body to reduce sweating.

It is best to eradicate cockleburs early in the season since they bloom only in the fall when the days are less than 14 hours long. Remove them from your garden, roots and all, and burn them. This is a tenacious plant that seems to resurrect itself under the most adverse of conditions and the only way to make sure it is dead is to destroy it completely. Composting may slow it down, but chances are, some will survive. The spiny seed pods remain prickly for some time and stepping on one when barefoot is no good experience (ask me how I know.)

The cocklebur is considered an aggressive plant, although not invasive here in North America, but its tendency to be invasive outside its native range has been demonstrated world-wide. Gardeners should remove them from their gardens quickly, before they reproduce. This is not a plant that you want to encourage and serves no use in a home garden at this point. There may have been some benefit to ancient peoples, but in this day and age, it is simply a thorn in the side (or foot), so don't encourage it.