This creeper goes by the common name of Batak vel and its botanical name is Aristolochia bracteolata. This beautiful bean shaped purple flower has dark striations and actually looks like a duck (batak). The plant flowers from July to December. The batak vel is said to be popular for these ornamental looking flowers. I am told that a rare variant has red flowers but I could not see that plant.
Seeds and roots of Aristolochia bracteolata are said to have medicinal properties. Click here and here for some more information. This link also has some information.