B. lepuznica is endemic to Romania and Serbia. In Romania, it occurs on Retezat, Borascu and Piule mountains in Hunedoara province, where the area of occupancy (AOO) is no more than 250 km², while in Serbia there is a single disjunct population close to the Romanian border on Mt. Vršačke above the city of Vršac (Banat region, Vojvodina province), c. 120 km west of the main area of the species' range in Romania.

The extent of occurrence (EOO) is no more than 7,500 km².