Redroot Pigweed (Amaranthus retroflexus) also known as: Green Pigweed, Rough Pigweed and Careless Weed  Division - Magnoliaphyta Class - Magnoliopsida Subclass - Caryophyllidae Order - Caryophyllales Family - Amaranthaceae Genus - Amaranthus      Taxonomic List List by Scientific Name List by Common Name |