Allergy Information

Because this weed is wind-pollinated, and a member of the same family as the notoriously allergenic ragweed, it is likely a source of allergy.

Genus Details

Cockleburs are annual weeds with branching strong stems and lobed leaves. The plants produce burs armed with spines. These spines serve as an excellent device for seed distribution. They hook onto animals that walk by and can be carried for miles. Likely not a source of allergies themselves, these burrs serve as temporary resting places for other pollen types just as leaves and branches do.

Pollen Description

Grains are mostly oblate-spheroidal to prolate-spheroidal. The amb is triangular, 3-4 lobate, pentagonal or hexagonal, and 3-4 colporate. Spinules are reduced to small pointed or blunt projections less than 0.6 micrometers long.

Pollen grains are 26-28 micrometers.

Genus Distribution

The shaded areas on the map indicates where the genus has been observed in the United States.

- Native, observed in a county 

- Introduced, observed in a county 

- Rarely observed