Common names: ground rattlesnakes, pigmy rattlesnakes, massasaugas.Sistrurus is a genus of venomous pit vipers found in Canada, the United States and Mexico. The name is a Latinized form of the Greek word for "tail rattler" (Σείστρουρος, Seistrouros) and shares its root with the ancient Egyptian musical instrument, the sistrum, a type of rattle. Three species are currently recognized.