Creeper vine climbing a tree trunk. Psychotria genus in the family Rubiaceae (the species is unidentified).
If you can identify the exact species, please post a comment or email me!
For more information about Psychotria, read en.wikipedia.org/wiki/Psychotria
Spotted along the jungle trail to Camp 5 in Gunung Mulu National Park (Borneo)
Photo processed in True Tone HDR with Tone Mapping from a single RAW exposure.