Unravelling the identity of Sindora(Fabaceae, Detarioideae) trees in the historical landscapes of Singapore

Sindora Miq. is a noteworthy genus in Singapore, with records of its existence, both natural and cultivated, dating back to the colonial period. Among which was the iconic‘Changi Tree’, an approximately 76 m tall tree at Changi that was felled in 1942 during WorldWar II. With the recent revision of the genus in Singapore, it was timely to survey the key historical landscapes at the Singapore Botanic Gardens (SBG), Fort Canning Park (FCP) and Changi Village Estate (CVE) for Sindora trees that are currently found or were once present in these locations. This was done through a site survey of the three areas, a study of herbarium specimens, literature and pictorial records relating to these areas, and the carbon dating of selected trees to ascertain their ages. At least 26 mature Sindora trees were recorded from this study, with at least 23 from SBG, one from FCP and two from CVE. Eighteen of these trees have been lost over time, leaving a total of eight trees consisting of an individual of Sindora siamensis Teijsm. ex Miq. and five of Sindora wallichii Benth. from SBG, one Sindora siamensis from FCP and one Sindora × changiensis L.M.Choo et al. from CVE. The latter is a hybrid of Sindora coriacea (Baker) Prain and S. echinocalyx Prain, recently elucidated using molecular tools. The identity of the ‘Changi Tree’ could not be fully verified, but it was likely to have been a Sindora echinocalyx based on a herbarium specimen collected from Changi. This study highlights the conservation value of trees in historical landscapes in Singapore, their importance in contributing to the genetic diversity of species in Singapore outside of nature reserves, and their role as a living legacy of Singapore’s rich botanical and horticultural history.