Azemiopinae is the name of a monotypic subfamily created for the genus Azemiops that contains the venomous viper species A. feae and A. kharini. No subspecies are recognized. The first specimen was collected by Italian explorer Leonardo Fea, and was described as a new genus and new species by Boulenger in 1888. Considered to be one of the most primitive vipers, it is found in the mountains of Southeast Asia in China, southeastern ***** and Vietnam. Its common name is Fea's viper.