In memory of Mary Mendum, who had helped me identify this plant many many years ago.
Aeschynanthus albidus is a large shrubby epiphyte which has glabrous green leaves with bright pink underside. I have seen the plant only once growing high in the canopy at the forest edge, exposed to bright sun. It is supposedly closely associated with ant nests. Unlike most other "lip-stick" vines, this one has green flower, usually borne in pairs along nodes of the vine.