ABOVE: Aglaia cucullata seeds collected from Serasa beach in Brunei Bay. Even though A. cucullata seeds do not grow on sandy beaches these distinctive seeds are a regular component of the drift seeds on sandy shores.
Caroline Pannell in Tree Flora of Sabah and Sarawak 6 pg. 85+ lists Aglaia cuculata habitat as the back of mangroves. In addition Aglaia rubignosa grows near rivers and freshwater swamps and Agalaia lancefolius and Aglaia rivularis are both rheophytes. Obviously the seeds of all these species are river dispersed and could easily turn up in the flotsam and jetsam on Borneo’s beaches.