The RBGE has a number of Aeschynanthus clambering over rocks, rooting into moss. This is likely quite characteristic of a natural growth habit for some members of the genus.
Note the orangish calyces on this species, which is otherwise quite typical of the “Lipstick Plant” Aeschynanthus commonly available in nurseries (e.g. A. lobbianus). These calyces are more prominently visible in a photo here and here.
A similar species with red flowers and calyces can be seen here.