 A relict species nearly exterminated by the last ice age, box huckleberry is self-sterile, and is found in isolated colonies which reproduce clonally by extending roots.One colony in Pennsylvania was once estimated to be as many as 13,000 years old; more recent estimates have an upper bound of about 8,000 years, which would make it the oldest woody plant east of the Rocky Mountains.Another colony in Pennsylvania, about 1,300 years old, has been protected by the Hoverter and Sholl Box Huckleberry Natural Area.