Dear Sir, Arunachal Pradesh is blessed with a cultural diversity of more than 30 major tribes and most of them are also good at speaking Assamese language. Most of the times, its a connecting language between people belonging from two different communities.
The most popular name for Rhynchostylis retusa in Arunachal is Kopou phool only. However, there are many other local names used by different indigenous communities. Regards, Ritesh.