prune malgache/prunier café/prune de Chine (French), Batoko/Madagaskarpflaume (German), ciruela de Madagascar (Spanish), ta khop thai (Thai), rukam (Malay), rukem (Indonesian)
(Flacourtia rukam — Family Flacourtiaceae)
Rukam comes from a tree of the same genus as ramontchi and lovi-lovi.
Native to Asia and Madagascar, it is often found naturalized throughout the Asian tropics, but it has been introduced to the American tropics and subtropics.
The roundish fruits are about an inch in diameter, and, when ripe, nearly black in colour. They have a yellowish white pulp, with a juicy but acidy taste.
They vary in sweetness, but there is at least one variety which is good to eat raw. Most are made into jams.
Another species, F. cataphracta, the paniala, is cultivated in the Far East, but has been introduced to the New World. Its fruits are cherry-sized and a russet-purple colour which resemble the rukam.