Dryobalanops is a genus of the family Dipterocarpaceae, with a total of 7 species distributed in Sumatra, Peninsular Malaysia and Borneo (Ashton et al., 1982). Only three species of Dryobalanops are found in Peninsular Malaysia; these are D. aromatica, D. oblongifolia and D. beccarii. Locally, D. aromatica is known as kapur, D. beccarii as kapur bukit, and D. oblongifolia as keladan.
These three species share the same characteristics of having deep green leaves, with numerous parallel veins. The leaves of these three species, however, differ in their shape and size. Kapur has thick, leathery, broadly ovate leaves measuring 4 to 6 cm long and 2 to 4 cm wide while kapur bukit has thinner, leathery, oblong lanceolate to ovate lanceolate leaves measuring 5 to 8 cm long and 1 to 3 cm wide. Keladan has oblong shaped leaves measuring 6 to 11 cm long and 2 to 4.5 cm wide. In fruit characters, D. aromatica and D. beccarii have 5 calyx lobes, 4 to 6 cm long, which expand into wings while D. oblongifolia has calyx lobes which are shorter than the nut.
Dryobalanops aromatica is found in Sumatra, Peninsular Malaysia and Borneo. The species epithet, aromatica is derived from the Latin word, ‘aromaticus’ meaning spice-like, referring to the aroma of the dammar or resin. Both the cut wood and crushed fresh leaves produce the aromatic scent (Ashton et al., 1982). Naturally, Kapur grows in clusters on well-drained soil on hillsides, and exhibits the ‘‘crown shyness’’ phenomenon where the tree crowns do not overlap or come into contact with one another (Chew, 2014).
In its natural habitat, Kapur can grow into a large tree of up to 60 m height with buttresses. The diameter of the bole can reach 3.4 m and the bark surface is longitudinally fissured. Kapur tends to flower once every 2 to 7 years depending on the presence of a prolonged dry period. Its flowers are white to cream in colour with glabrous and oblong petals. Each flower has 30 stamens that are shorter than the style. The fruit is a 5-winged nut with wings up to 6 cm long. The seeds and cotyledon-stage seedlings are often consumed by vertebrates such as rodents and wild pigs (Kachi et al., 1995).
Kapur is an important source of timber in Peninsular Malaysia and Sumatra. Its medium hardwood is highly valued for construction due to its attractive pale brown colour and is used locally for construction of walls and floors of houses. A clear yellow and aromatic liquid, known as camphor oil, is produced from the trunk of young trees, and through the process of crystallization forms true camphor. Camphor is used for its scent in religious ceremonies, in perfumery and aromatherapy, as an ingredient in cooking (mainly in India), and for medicinal purposes. A powder of the fruit kernel is used in local remedies, especially for stomach ache and for staunching blood flow (Soerianegara & Lemmens, 1994).
Although Kapur is considered Near Threatened (NT) for Sabah and Sarawak due to decreasing populations, it is considered Least Concern (LC) for Peninsular Malaysia because it grows gregariously in areas where it is found naturally. Overall, it has been evaluated in the Malaysia Plant Red List Book as Near Threatened for Malaysia (Chua et al., 2010).
