Although this shallow-rooted annual can become unsightly in turf, it is probably most disliked for its pungent, offensive odor. This odor, which is caused by flower pollen, is particularly disturbing to sufferers of "hay fever". Ragweed reaches maturity in late summer, when unwatered turf becomes dry and parched. Leaves are flat and fernlike in appearance, somewhat resembling the outline of an evergreen tree. Male and female flowers are produced on different parts of the plant. Female flowers are found in the axils of the leaves, while male flowers grow in clusters at the top of the uppermost branches.