Buta-buta (Excoecaria agallocha)

The Buta-buta (Excoecaria agallocha) is a common mangrove tree from the family Euphorbiaceae. It is also commonly called "Blind-your-eyes", due to its poisonous sap.


This mangrove tree can be seen at most, if not all, of our major mangrove forests, such as Pulau Tekong, Pulau Ubin, Pasir Ris, Mandai, Lim Chu Kang, Sungei Buloh Wetland Reserve, Kranji, Khatib Bongsu, Pandan, Woodlands Town Garden and Pulau Semakau, among others.


It usually occurs on the landward margin of mangrove forests, especially in areas with freshwater inputs. The roots run along the surface of the soil, are often knotted.


The trunk is greyish or brownish, and somewhat warty. Bark and roots are covered with lenticels for air exchange.


It has simple, alternate, elliptic leaves with a pointed tip and toothed-margin. Poisonous white latex is present in trunk, stems and leaves, and can cause blistering and (temporary) blindness.


The tree is deciduous, and leaves turn yellow, orange or even reddish before they are shed.


The tree bears either male or female flowers. The tiny flowers are spirally arranged on catkin-like, elongated clusters. Male inflorescences are longer (up to 11cm).


Female inflorescences are shorter (up to 4cm long).


The fruit is a capsule with 3 lobes and compartments, each with 1 seed.

The poisonous sap is used to stun fish. The wood is used for carving, making matchsticks and sulphate-paper pulp. It is not used for firewood due to its unpleasant smoke.

References

• Chong, K. Y., H. T. W. Tan & R. T. Corlett, 2009. A Checklist of the Total Vascular Plant Flora of Singapore: Native, Naturalised and Cultivated Species. Raffles Museum of Biodiversity Research, National University of Singapore. Singapore. 273 pp.
• Giesen, W., S. Wulffraat, M. Zieren & L. Scholten. 2006. Mangrove guidebook for Southeast Asia. RAP Publication 2006/07. FAO Regional Office for Asia and the Pacific & Wetlands International. Bangkok. 769 pp.
• Ng, P. K. L. & N. Sivasothi. 1999. A guide to the mangroves of Singapore 1 : the ecosystem & plant diversity. Singapore Science Centre. Singapore. 168 pp.