Sistrurus

Common names: ground rattlesnakes, pygmy rattlesnakes, massasaugas

Sistrurus is a genus of pit vipers in the subfamilyCrotalinae of the familyViperidae. The genus is endemic to Canada, the United States, and Mexico. Its generic 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.