Pentaspadon motleyi is known in Malay as Pelong licin. The epithet for the genus Pentaspadon is derived from the Greek words ‘penta’ meaning five and ‘spadon’ meaning eunuch, which refers to the five sterile stamens in the flowers. The species name motleyi honours James Motley, a 19th century English plant collector in Borneo (Soepadmo et al., 1996).
Pentaspadon is a small genus containing only nine species in the family, Anacardiaceae, which also includes common species such as cashew, mango and pistachio. Pentaspadon motleyi is widely distributed in Malaysia, Indonesia, Papua New Guinea and the Solomon Islands. The tree is often found in swamps, primarily along rivers and streams, up to 200 m altitude (Adnan et al., 2018).
Pentaspadon motleyi is a large tree that can reach up to 50 m tall and 70 cm in diameter, with a spreading canopy and slender buttresses. The outer bark is grey-brown and scaly, while the inner bark is pink and produces a whitish sap when cut. The species has compound leaves with 4 to 5 pairs of leaflets which are spirally arranged, clustered at the end of the twigs, and pinkish in colour when young. The leaflets are oblong-elliptic in shape, oppositely arranged, 5 to 13 cm long and 2 to 6 cm wide, with pointed tips and rounded bases. The leaflets have about 6 to 10 pairs of secondary nerves and hairy domatia (small leaf cavity inhabited by insects or mites) in their axils (Lim, 2012). The leaf stalk is usually red when young, turning green when mature.
The inflorescence is 30 cm long and formed in the shoot terminal. Flowers are yellowish white and small in size, 4 mm in diameter. It flowers twice annually from March to May and subsequently in October until November (Ng, 1989). When in bloom, the spreading canopies are dense with flowers. The flowers are bisexual with a 5-lobed calyx and petals overlapping like tiles, and 5 fertile stamens alternating with 5 sterile stamens (Lim, 2012). The fruits are fleshy, contain a single large seed with a hard cover (drupe), ovoid, about 3 to 5 cm in length and 2 to 2.75 cm in width. The fruits are green with brown dots when fresh, turning dark brown with pale brown dots when ripened (Hong, 2003).
Pentaspadon motleyi is grown as an ornamental tree in parks and gardens providing shade and a beautiful sight when in full bloom. The fruits can be eaten fresh, roasted, fried or boiled (Lim, 2012). Ex-situ conservation or living collections of this species can be found at the Kepong Botanic Garden, Non-Dipterocarp Arboretum, and a few research field plots in FRIM. The conservation status of this species is categorized as Data Deficient in the IUCN Red List (WCMC, 1998).