Western ragweed is a native perennial forb in the Asteraceae plant family. It is readily recognized by its grayish green leaves and dense foliage. Western ragweed is found throughout the prairies, and is an indicator of disturbance. Flowering occurs from July to October.
It is found across North America, excluding the Rocky Mountains.
Western ragweed is a very important plant for wildlife. Several species of wildlife use it for cover. It is also a very important food source for several prairie bird species. They consume its seeds which are very abundant. Cottontail rabbit, pronghorn and white-tailed deer consume the leaves and stems of western ragweed.
Cattle consume western ragweed in the early spring, when it is palatable. Although it is perceived to have negative impacts on cattle grazing and is often sprayed with herbicide; research from Oklahoma and Kansas has shown that it is not a serious competitor with native grasses.
Native Americans used the leaves for tea to relieve stomach cramps, diarrhea and sore eyes.
Western ragweed produces pollen that can cause severe hay-fever in many humans.