Seeds 0.6–1 x 3 cm. including the wings.
Branches 4-angled, grooved minutely lepidote, pubescent only at the nodes.
Scandent shrubs up to 10 m. high or subshrubs.
Leaves imparipinnate, 13–27 cm. long, 4–7-jugate; petiole 2–6 cm. long; leaflet lamina 3.5–9 x 1.3–2.6 cm., narrowly ovate to ovate-lanceolate, longly acuminate at the apex, rounded to somewhat asymmetric at the base, grass green, inferior surface slightly lighter and glandular, margins entire or sometimes serrate-crenate uni- or bilaterally along the distal half; petiolules up to 1.5 cm. long in proximal pairs, decreasing progressively upwards.
Inflorescence a few- to many-flowered terminal panicle, up to 40 mcm. long, glabrous, branches opposite and decussate; pedicels 1–2 cm. long, articulated c. 3.5 mm. from the top, upper articulate, falling off with the flower, the lower persistent and 2-bracteate towards the base.
Calyx whitish, campanulate, 5-ribbed, inflated, 5-lobed, lobes triangular-oblong, 0.6–1.2 x 0.4–0.7 cm., apiculate at the apex and revolute, tube 0.7–1.5 cm. long, glabrous outside and minutely glandular inside.
Corolla campanulate, mauvish pink, throat brighter and carmine streaked inside; corolla tube 3.5–5 cm. long, cylindrical at the base c. 1 cm. long suddenly campanulate near the top, glabrous outside and villous inside, limb 5-lobed, bilabiate, lobes 1.3–2.8 cm. diam., almost circular, margin ciliate and pilose at the sinus.
Stamens didynamous, included, with the staminode between the shorter pair; filaments adnate up to 1 cm. from the base of the corolla tube, densely pilose at the insertion points; anther-thecae divergent when mature, the connective apiculated and dorsaly crested.
Disk c. 1 mm. long, annular-cupular.