Amaranthus tuberculatus (Moq.) Saur (syn.  A. rudis Sauer) Also known as common waterhemp; tall waterhemp; pigweed; roughfruit amaranth Biology Waterhemp is a summer annual plant, relying upon yearly seed production for persistence. It is one of the few problematic dioecious weeds in US cropping systems, which means that male and female flowers occur on different … Continue reading Waterhemp