ໝາກຕຸມກາ / Strychnine

Seng beua is a deciduous tree 5-25 m tall with a spreading crown and a DBH of 15 cm. The grey bark has thin horizontal rings and is slightly flaky. The twigs are yellow-grey, sometimes with spines. Leaves have stalks of 5 -11 mm and broadly egg-shaped blades, 4-10.5 x 3-8.6 cm, thin, papery and shiny on the top. The inflorescence-stalks are light-brown and hairy, 2.5-5.5 cm, with many yellow-greenish flowers sized 8-13 mm. The bright yellow-green fruit turns reddish when ripe, and is hard with a thick skin. It is 2.5-4 cm in diameter and white inside, with one to four seeds, each 2.1-2.2 cm. These seeds look like flattened discs, about 6 mm thick, and are densely covered with hairs which give them a shiny appearance. The seeds are very hard and consist of a large, dark grey endosperm. They have no odour but a very bitter taste. This species is easily confused with Strychnos nux-blanda, which has larger fruit measuring 5-8 cm.