Aeschynanthus hildebrandii

Unknown photographer, courtesy RBGE 
Grown at Royal Botanic Gardens, Edinburgh

This is the true A. hildebrandii.  Material once widely distributed under this name was correctly A. humilis.  This photo illustrates the difference in the flowers of these similar species.  Another photo of A. hildebrandii can be seen here.  A comparison of the flowers of the two species clearly illustrates distinct differences.