spiny pigweed Directory References Discover Why Is the Mona Lisa So Famous? The World’s 5 Most Commonly Used Writing Systems Timeline of the American Civil Rights Movement The Seven Sacraments of the Roman Catholic church Which Religion Is the Oldest? Timeline of the Space Race, 1957–69 How Deadly Is Quicksand? Contents spiny pigweed plant Ask the Chatbot a Question Ask the Chatbot a Question Also known as: Amaranthus spinosus, spiny amaranth Learn about this topic in these articles:pigweed In pigweed…stems rising at the tips; spiny pigweed, or spiny amaranth (A. spinosus), has spines at the base of the leafstalks; and rough pigweed, or redroot (A. retroflexus), is a stout plant up to 3 metres (about 10 feet) tall.Read More