Acacia catechu is a deciduous tree with a light feathery crown and dark brown, glabrous, slender, thorny, shining branchlets, usually crooked. Bark dark brown or dark grey, brown or red inside, nearly 12-15 mm in thickness, rough, exfoliating in long narrow rectangular flakes which often remain hanging. Blaze very hard, colour brown and then deep pink. Branchlets armed with pseudo-stipular spines in pairs below the petioles. Pod 10-15 cm by 2- 3 cm, thin, straight, flat, glabrous dark-brown and shining when mature. Seeds 3-8, about 5 mm in diameter.