The genus Rhododendron is considered one of the relictual plant taxa having circumboreal distribution.
However, through vicariance followed by orogeny, the distribution of this plant genus was vastly affected. A total of
forty six Rhododendron species in Bhutan Himalayan region share most of its species with central Himalayan countries.
Additionally, the genus Rhododendron is found even to the extend to Far East Asia. However, very little information is
available on the comparative study of the phytogeographic distributions of genus Rhododendron between Himalayan
countries and the extent of East Asia. Various literatures and derived data on the Rhododendron species availability
were studied. Findings revealed that the Rhododendron arboreum is found to be widely distributed across the whole
Himalayan range to the neighbouring countries in East Asia. It could be reasoned that Rhododendron species of
Himalayan range are confined within their geographical boundary and remain isolated from other populations. We
proposed that heterogenous environmental condition offered by might have played an important role in sustaining
the diversity of Rhododendron in Himalayan range. Although Bhutan Himalayan range is not accounted a center of
distribution of Rhododendron species, it might have helped as an important corridor for the dispersal of plant elements
as it connects many floristic region and biogeographic realms.