Learning more about mangroves from Dr Jean Yong, and recalling Joseph Lai's documentation of Sentosa's coastal plants in our Sentosa Survey of 2006, I just had to have a closer look at them! Today, after the TeamSeagrass monitoring, Siti, Wei Ling and I paid them a visit.
These two magnificent trees are Xylocarpus rumphii, very rare trees in Singapore! In his article for Nature Watch, Jean Yong shared that "The last time this species was counted (1996), there were three mature trees and twelve young plants. " According to Hsuan Keng, it has been recorded on rocky coasts of Singapore. The species is now listed as 'Critically Endangered' on the Red List of threatened plants of Singapore.
While Singapore's two other species, Xylocarpus granatum (still quite common) and Xylocarpus moluccensis (listed as 'Endangered') are found in mangroves, Xylocarpus rumphii is found on rocky shores. And there are fewer of such suitable habitats left for X. rumphii.
Xylocarpus rumphii has fissured bark (while X. granatum has peeling bark, and X. moluccensis also has fissured bark.)
Xylocarpus rumphii doesn't have specialised roots (while X. granatum has snaky buttress roots, and X. moluccensis has short buttresses and peg-like pneumatophores)
The leaves of Xylocarpus rumphii are almost heart-shaped with obvious pale veins (while X. granatum has leaves with rounded tips, and X. moluccensis has sort of eye-shaped leaves.)
This is the typical form of the young fruits of X. rumphii.
According to Giesen, among its uses are the wood for handles of traditional knives (kris) and in building boats, the bark for tanning and dyeing cloth. The seeds are used to treat stomachache.
The presence of trees such as Xylocarpus rumphii and Tongkat Ali and many other endangered and rare plants and animals makes this Sentosa shore very special indeed.
- The Struggle for Survival: Five threatened coastal plants once common on our shores by Jean W H Yong, Nature Watch Vol 6 No 1 Jan-Mar 98
- Hsuan Keng, S.C. Chin and H. T. W. Tan. 1990, The Concise Flora of Singapore: Gymnosperms and Dicotyledons. Singapore University Press. 222 pp.
- Davison, G.W. H. and P. K. L. Ng and Ho Hua Chew, 2008. The Singapore Red Data Book: Threatened plants and animals of Singapore. Nature Society (Singapore). 285 pp.
- Giesen, Wim and Stephan Wulffraat, Max Zieren and Liesbeth Scholten. 2006. Mangrove Guidebook for Southeast Asia (PDF online downloadable). RAP publication 2006/07 Food and Agriculture Organization of the United Nations Regional Office for Asia and the Pacific Bangkok.