Stereospermum kunthianum is a deciduous shrub or tree, 3-15 m high, with
a stem diameter of 25 cm; bark thin, grey to grey-black, smooth or
flakes off in patches resembling the European plane tree; trunk rarely
straight, mostly forked; branches twisted; branching is erect and
spreading to form a light, rounded crown. Slash white or light brown.
Leaves imparipinnately compound, 25 cm long, alternate with 2-4 (max. 6)
almost opposite pairs of leaflets and 1 terminal leaflet; 5-9 leaflets
with short, soft hairs, oblong to oblong elliptic, stiff, 5-8(max. 10) x
3-7.5 cm, green and hairless above and yellow-green with prominent
veins under; apex broadly tapering, often abruptly attenuate; base
tapering; margin entire, occasionally toothed in coppice growth;
petiolules almost absent; petiole up to 7 cm long, caniculate at the
top; young leaves sometimes toothed and hairy. Flowers precocious,
fragrant, bisexual, showy, mauve to off-white, more usually pinkish with
red streaks on the lower corolla lobes and produced in large, drooping
panicles on long peduncles; corolla with a tube up to 3 cm long and
spreading lobes, 3-4 cm in diameter; calyx bell shaped, irregularly 2-
to 5-lobed, partially forming 2 lips; stamens 4, enclosed within the
corolla tube; ovary linear-oblong, 2-chambered. Fruits slender, flat
capsules or paired pods up to 45 x 1 cm, cylindrical, greenish-purple,
reddish-brown to dark brown, pendulous, spirally twisted, smooth,
splitting into 2 valves to release many flat, long, narrow, winged
seeds. The remnants of the capsule remain on the tree for months.
Raman
