Tengkawang is local name of some trees in Shorea species, which is small part of the 267 species of Dipterocarpaceae in Kalimantan (Ashton,1982). Tengkawang dispersed mostly in Borneo and slightly in Sumatera. Several Tengkawang species or commonly classified as Red Meranti are included Shorea macrophylla, S. stenoptera, S. seminis, S. beccariana, S. mecystopteryx, S. palembanica, S. pinanga, and S. plendida. Tengkawang has important role to maintain the ecological balance of the ecosystem.
Tengkawang’s blooming period is not known certainly yet, and dwindling in its natural habitat as a consequence of logging practices and high levels of deforestation. Tengkawang is formerly easy to find, but now it becomes scarce. 13 species have been declared protected from extinction by PP No.7/1999 and prohibited to harvest according to Ministerial Decree No. 692/Kpts-II/1998. Some studies of Direc have shown that over the last few years from 13 Tengkawang protected species, 7 species have been very difficult to find in their natural habitat and are probably headed to extinction. The impact of harvesting and forest fragmentation caused a decreased or even loss of genetic diversity in species and population level, changes in population structure increasing possibility of inbreeding and genetic drift. This condition leads to the preservation of genetic diversity to be vulnerable , so that strategic action to conserve the genetic diversity of Tengkawang species is needed.