Gracinia atroviridis Griff. ex T.Anderson, Fl. Brit. India 1: 266 (1874)

Synonyms

Diagnostics
The Asam Geluger tree grows to a height of more than 20 m and has a long trunk, smooth grey bark and drooping branches. The leaves are dark green, shiny, long and narrow with a pointed tip and upturned edges. The flowers are dark red. The round fruits are borne singly on twig ends about 7-10 cm in diameter. The ripe fruits are bright orange yellow and ridged.

Description
Tree, up to 20 m tall, with white to yellow sap. Stipules absent. Leaves opposite, with petiole clasping around the twig. Leaves elliptic, venetion unclear, with resin canals when held against the light. Flowers in dense clusters, usually with just a few flowers, flowers red coloured. Fruits yellow-orange when ripe, ca. 7-10 mm diameter, with longitudinal ridges.

Ecology
In evergreen forests. Commonly found in evergreen forests in the southern region of Thailand and Malaysia.

Uses
Sun-dried slices of the fruits, locally known as "asam keping", are commercially available and are popularly used as a vegetable salad and is considered extremely sour. The fruit is sliced, dried then stewed and used as a common ingredient in Asian dishes such as curries and soups. Used frequently in Thai medicine as an acidic fruit for reducing weight and excess fat by stopping the glycogen process (thereby converting fat to energy).

Distribution
This species grows wild throughout peninsular Malaysia and southern Thailand but is also widely cultivated, especially in the northern states, owing to its economic and medicinal value.

Local names
Malaysia: Asem gelugo, Asem gelugur, Asem keping.