Bersama tysoniana is a shrub or a small to medium-sized tree, usually 3 to 10 m high, sometimes growing up to 15 m high. The bark is thick, wrinkled, and grey-brown. Leaves are compound, 70–250 mm long, with 4–6 pairs of opposite leaflets plus a terminal one; petioles up to 50 mm long. Leaflets elliptic, ovate or obovate, 15–19 × 7–40 mm, apex rounded or pointed, dark green, veins prominent below, hairless or hairy on both surfaces; margin entire or finely toothed over the upper half; petiolules (stalks) short. Young leaves densely hairy and red-brown. Inflorescences produced before or with new leaves, in dense terminal racemes, up to 250 mm long, on short or long, hairy stalks.

Flowers small, greenish to cream-white and sweetly scented, in spring and early summer (August–December).

Fruits knobbly, woody, roundish, brown capsules, up to 30 mm in diameter, splitting into 4 parts; seeds reddish orange with yellow arils at the base, in late summer, autumn and winter (February to August).