Vipera berus bosniensis, the Balkan cross adder[2] or Bosnian viper,[3] is a venomous subspecies of viper[4] endemic to the Balkan Peninsula.

[5] It is only found within the Balkan Peninsula, particularly the Herzegovina region of Bosnia and Herzegovina, hence its common name.

[5] McDiarmid et al. (1999) follow Golay et al. (1993) and recognize V. b. bosniensis as a subspecies of V.

berus.

[1] However, it has been considered a full species in recent literature.