Lepisanthes rubiginosa, commonly known as mertajam in Malay, is a shrub or small tree from the family Sapindaceae. The genus name comes from the Latin word, lepis which means scale and anthos, referring to the flower, describing the flower which has scales on the inner surface of its petals. The species name, rubiginosa means rust-coloured, referring to the rusty brown indumentum of the leaflets and twigs (Adema et al., 1996).
Lepisanthes rubiginosa can be found from North India to Indo-China and South East China, throughout Malesia, to North-west Australia. In Malaysia, this species can be found in all states. This tree is common in coastal forest or on islands, or in the transition zone between mangrove and dry land. It can also grow in inland lowland forest, by streams, in secondary forest and wastelands, up to 300 m altitude.
Mertajam can grow up to 16 m tall with diameter of up to 28 cm at breast height. The compound leaves are elliptic-ovate with 2-9 pairs of velvety hairy leaflets. The leaflets are elliptic, oppositely or sub-oppositely arranged, 6.5-18 cm long and 3.5-8.5 cm wide, with rounded base and obtuse to acute or acuminate apex. The flowers are small and white in colour. The very fragrant flowers are visited in abundance by stingless Trigona bees (Van Welzen, 2017). The infructescence are unique because they have a variety of colours caused by the uneven ripening of the fruits. The fruits are small, green when young, turning yellow, reddish and finally dark purple to nearly black when fully ripe (Adnan et al., 2018).
This species is popular among villagers and sometimes it is cultivated as an ornamental tree along roadsides in villages. The fruits are edible and relished as a snack, mainly by children. The timber is said to be valuable, but in Malesia it is used only for firewood (Adema et al., 1996). The conservation status of this species is Least Concern (Van Welzen, 2017).