Assertion: pit viper | /r/HasProperty | crotalinae
Facets:
Source sentences:
text: There are four subfamilies of viper snakes -- Fea's vipers (Azemiopinae), night adders (Causinae), pit vipers (Crotalinae) and true or pitless vipers (Viperinae).
text: There are two primary groups of venomous snake in the U.S.: pit vipers (Crotalinae), which include rattlesnakes, copperheads, and cottonmouths