The monospecific Endosamararacemosa was recognised at generic level by Geesink (1984: 93) principally by its unique fruits with their seeds forming segregating loments encased in endocarp each with a flat wing, a unique feature within the tribe. Endosamara has stipules 6–12 mm long (vs. 3–7 mm in Sigmoidala and 1–6 mm in Calleryas.str.), lacks floral bracteoles, has glabrous ovaries and glabrous standard petals (vs. back of standard pubescent in Sigmoidala).

Endosamararacemosa (Roxb.) Geesink ≡ Robiniaracemosa Roxb.

robust, twining woody vine. Stems green when young, terete, pubescent, mature stems pale brown, glabrous. Leaves with 7–13 leaflets, evergreen, coriaceous when mature, imparipinnate, rachis 10–24 cm long. Stipules 6–12 mm long, narrowly lanceolate, persistent, becoming woody and spinose on old branches. Stipels 3–6 mm long, linear, persistent. Leaflets 5–13 × 2–7 cm, oblong-obovate, elliptic, glabrous above, tomentose below becoming glabrous, apex acute, margins entire, base obtuse to cuneate. Inflorescence a robust many-flowered terminal panicle 20–50 cm long, peduncle densely silvery-brown hairy. Flowers 12–16 mm long, emerging from March – June. Floral bracts 6–15 mm long, caducous, densely pubescent, linear-lanceolate. Bracteoles absent. Pedicels 3–6 mm long, densely pubescent. Calyx 3 × 6 mm campanulate, green, densely puberulent externally, five lobed, lobes ± equal, 1–3 mm long, broadly acute, obtuse or subtruncate, becoming more fleshy and rounded at maturity. Standard 10–15 × 12–15 mm, suborbicular or broadly ovate, inner surface pale to dark pink, pinkish purple, rarely white, nectar guide greenish yellow, back of standard glabrous, apex acute or emarginate. Callosities of boss type. Wing petals 12–13 × 3–5 mm, glabrous, slightly longer than keel, each narrowly semi-pandurate, slightly curved upwards at the apex with basal claws 3 mm long. Keel petals 10–12 × 4–6 mm, glabrous, united into a falcate, navicular cup, apex obtuse. Stamens diadelphous, nine fused together, the vexillary one free, all curved upwards at apex. Ovary glabrous, style glabrous, 4–5 mm long, curved upwards at apex, stigma punctate. Pods 8–25 × 1–2 cm, green, flattened, linear, dehiscent, exocarp raised above the seeds, surface glabrous, black when dry, internally septate. Seeds 4–5, 10–12 × 6–8 × 5 mm, oblong, short beaked at one end, each seed separated inside the pod, entirely covered in a thin chartaceous layer of endocarp one side of which extends into a papery samaroid wing forming a compartmented unit that becomes free on maturity, wings 3–5 × 1 cm, hilum eccentric at beaked end of seed, broadly elliptic 2–3 × 2 mm.