Cycloloma

Cycloloma is a monotypic genus which contains the sole species Cycloloma atriplicifolium, which is known by the common names winged pigweed, tumble ringwing, plains tumbleweed, and tumble-weed. This plant is native to central North America, but it is spreading and has been occasionally reported in far-flung areas from California to Maine to the Canadian prairie. It is considered an introduced species outside of central North America. This is a bushy annual herb forming a rounded pale green clump which may exceed half a meter in height. It is very intricately branched, with toothed leaves occurring near the base. The spreading stems bear widely spaced flowers are small immature fruits fringed with a nearly transparent membranous wing. In autumn, the plant forms a tumbleweed. The fruit is a utricle about 2 millimeters long containing a single seed.