This plant has climbed up trees for about 2 or 3 meters. It is in someone's section, so I could go no closer. The second photo shows the flowers more clearly.
Apocynaceae is a family of flowering plants that includes trees, shrubs, herbs, stem succulents, and vines, commonly called the dogbane family. Members of the family are native to European, Asian, African, Australian and American tropics or subtropics, with some temperate members.