Aeschynanthus obconicus

Photo by Leong Tuck Lock
Grown in nature, Kampar, Malaysia

A. obconicus is a somewhat variable species, but always characterized by saucer-like calyces, which are usually the same bright red as the flowers.  A photo of the whole plant, clambering over a boulder can be seen here.  Other photos of plants growing in cultivation can be seen here, here and here.