Shorea is the biggest genus in the family of Dipterocarpaceae and is divided into several main groups i.e., Balau, Temak Batu, Meranti pa’ang, Meranti Damar hitam and Red Meranti. Shorea siamensis is the only species in the Temak Batu group. Previously, this species was placed in its own genus, Pentacme.
Shorea siamensis inhabits the deciduous forests of Burma, Indochina, Thailand and Malaysia. In Malaysia, it is restricted to the northern part of the peninsula i.e., in Perlis coast and Langkawi Island. Shorea siamensis is xerophilous; it can adapt and survive in a dry climate and habitat. The conservation status of this species in the IUCN Red List and the Malaysia Plant Red List is Least Concern (Ashton et al., 1998; Chua et al., 2010).
The field characteristics of Shorea siamensis are quite variable according to its geographical habitat. Thus, some characteristics described might occur only to species found in Malaysia. A densely pubescent form of this species was recorded in Burma and Thailand (Symington et al., 2004). The trees of S. siamensis in Malaysia are usually small with trunk diameter of less than 1 m and normally have wide crowns. The trunk is usually gnarled with fissured bark, and small buttresses may be present. The leaf is ovate-rotundate, about 12 × 9 cm with a sub-cordate base and acuminate apex. The twig is slender and smooth when mature. The flowers are beautiful, about 2 cm wide and the petals are creamy white. The fruits have 2 major and 3 minor wings. Mature fruits are about 12 x 1.5 cm.
Temak Batu, the vernacular name for this species, refers to the density and compact texture of its timber. In the northern part of the peninsula, the word Temak is used by the locals to name certain Shorea spp. such as Shorea roxburghii which is known as meranti temak nipis and S. hypochra as meranti temak. Batu means stone that signifies the characteristic of its timber which is hard and compact. It is monospecific and categorised as hard to very hard and heavy timber (MTC, n.d.). As the locality of this species is confined to Malaysia and it is hard to obtain a long log because the stem is usually twisted, Temak Batu has little economic importance although the timber is almost the same quality as Balau.
Trees of Shorea siamensis were planted as living collections at the Dipterocarp Arboretum of FRIM, Kepong. These ex-situ trees flower almost annually, usually starting in December, and fruit from January to Mac. Based on author’s personal observations, the intensity of fruiting and flowering of these trees in the Dipterocarp Arboretum, between December 2020 and April 2021, was about 50% higher than that of from the end of 2019 to early 2020. This might be in accordance with the mass flowering event that occurred this year.
