The occurrence of a species or other taxon in two widely separated places, but nowhere in between. For example, the tulip tree genus (Liriodendron) has species in eastern North America and in China, but none in between, and southern beeches (Nothofagus species) occur in New Guinea and Australasia, and in Chile, on opposite sides of the Pacific Ocean, but nowhere else. A number of plants endemic (see endemism) to Scandinavia occur only in both of two widely separated montane areas, possibly reflecting the former existence of nunataks above the late Pleistocene ice sheet. Compare unicentric distribution.
Subjects: Plant Sciences and Forestry — Ecology and Conservation.