It’s a pigweed, right? Travis Legleiter, Weed Science
Professional Assistant, Botany & Plant Pathology Department The
term pigweed is often used to lump together all species within
the Amaranthus genera. Within the state of Indiana the most
prevalent and common Amaranth is smooth or redroot pigweed
(Amaranthus retroflexus). Although two new amaranth species are
likely to begin making their appearance in Indiana: Common
Waterhemp (Amaranthus Rudis) and Palmer amaranth (Amaranthus
palmeri). Common waterhemp has already become a prevalent
species in pockets of Indiana and is anticipated by Purdue weed
scientist to continue to spread throughout Indiana. Currently
only a few incidents of palmer identification has been reported
in Indiana and the potential spread is less anticipated as
compared to waterhemp. The identification of these individual
species can prove to be essential as waterhemp and palmer
amaranth are much more aggressive and capable of becoming
herbicide resistant as compared to the redroot pigweed