A tree. It grows 10-30 m tall. The trunk is straight and 150 cm across. It is slightly fluted. The bark is light grey and cracked and scaly. The leaves are compound with 3-4 pairs of leaflets. These are narrowly oval or oblong and 8-20 cm long by 3-8 cm wide. The base is unequal. They have a long point at the tip. The flowers are bell shaped and 7-8 cm long by 4-5 cm wide. They are hairy and have deeply fringed petals. They are lilac and hang down. The fruit is a cylinder shaped pod 37=75 cm long. It is rough, woody and twisted. It hangs from the branches and splits open. The seeds are flat and 2-3.5 cm long. They have wings at both ends.