Asam Gelugor ( Garcinia Atroviridis )

This fruit, which is native to Peninsular Malaysia, is a member of the Garcinia Family,
a family which also includes the highly prized fruit, the mangosteen.
The small round fruits of asam gelugor, which does not have a common English name, are very sour
and therefore not eaten fresh. Instead, they are thinly sliced and droed until
shrivelled and brownish black.

Asam gelugor, also known as asam keping (literally "sour slices"), is used
primarily in fish curries in Malaysia and Singapore. Its acidity and flavour
are subtlely different to the sour fruitiness of the more commonly used
souring agent, tamarind, but this can be substituted.

Another member of the sama family, a tree known as goraka in Souteast India
and Sri Lanka, produces a fruit used in similar ways to asam gelugor.
In Thailand, yet another Garcinia, G. schomburgkiana, shares the same sourness
as asam gelugor and is used fresh in some salads, and also in fish curries.
It is known in Thai as madan.

Botanical Family : Guttiferae
Thai name : Som khaek, sommawon
Malaysian name : Asam gelugor
Indonesian name : Asam gelugor

source : Hutton, Wendy; (1997); Tropical Herbs & Spices of Indonesia; Periplus Editions