Derris marginata (Roxb.) Benth.

         Lianas. Twigs 4–6 mm diam., glabrous, lenticellate. Stipules triangular, 2–2.5 x ca. 2 mm, outside thinly sericeous, inside glabrous. Leaves with 5–7 leaflets. Petiole 2.5–8 cm long, striate, glabrous; rachis 5.5–11 cm long, striate, glabrous; pulvinus 8–10 mm long, glabrous. Stipellae absent. Leaflets subcoriaceous to coriaceous; terminal one elliptic, 6–14.5 x 3.5–6.5 cm, length/width ratio 1.7–2.5, base obtuse to rounded, apex acuminate, acumen 8–14 mm long, rounded, upper and lower surface glabrous, midrib slightly raised in a furrow above, distinctly raised below, veins raised on both sides, 9–12 per side, 7–20 mm apart, not reaching the margin but curving upwards, sometimes anastomosing near the margin, venation reticulate; lateral ones mostly like terminal one, elliptic to ovate, 6.8–13.5 x 3.2–6 cm, length/width ratio 2.1–2.2; pulvinus 6–11 mm long. Inflorescences axillary, rarely terminal panicle, 12–22 cm long, peduncle 10–35 mm long, glabrous or thinly strigose, striate; lateral branches 2.5–14 cm long. Bracts subtending lateral branches triangular, 1.5–1.6 x 1.3–1.4 mm, outside glabrous to thinly sericeous, inside glabrous but with some hairs at base. Brachyblasts absent. Bracts subtending flowers elliptic to ovate, 0.9–1 x 0.4–0.6 mm, both sides glabrous or with few hairs, margin ciliate. Pedicels slender, 10–12 mm long, glabrous. Bracteoles at the upper part of pedicels, narrowly elliptic to ovate, 0.7–0.9 x 0.2–0.3 mm, both sides glabrous, margin slightly ciliate. Calyx reddish-green, cup-shaped, 2.5–3.7 mm high, both sides glabrous, margin ciliate, tube 2–3 mm high, upper lip indistinct or with 2 short lobes, 0.2–0.3 x 1.5–3 mm; lateral lobes triangular or semi-circular, 0.7–1 x 2–2.7 mm; lower lobe triangular or semi-circular, ca. 0.7 x 1.5–1.6 mm. Corolla whitish or pinkish. Standard: claw 3.3–3.5 mm long; blade broadly obovate to orbicular, basal callosities absent, 8–9 x 7–7.5 mm, apex emarginate, outside glabrous or with few hairs at the apex, inside glabrous. Wings: claw 3–3.5 mm long; blade elliptic, 8.3–9 x 1.8–2.2 mm, apex rounded, upper auricle 1–1.7 mm long, lower auricle indistinct, both sides glabrous. Keel petals: claw 2.5–3 mm long; blade boat-shaped, 7–7.3 x 2.7–3.1 mm, apex rounded, glabrous, upper auricle indistinct, lateral pocket 1.5–2 mm long. Stamens monadelphous, with basal fenestrae, 10–10.5 mm long, free part 1.5–2 mm long, glabrous; anthers ca. 0.3 x 0.2–0.3 mm, glabrous. Disc annular, more or less distinctly (5–)10-lobed, up to 0.3 mm high. Ovary 4–5 mm long, stipe indistinct, glabrous to thinly sericeous; ovules 4 or 5; style 3–3.5 mm long, glabrous. Pods elliptic to strap-like, 7–10 x 2.5–3.5 cm, glabrous, with wing along both sutures, upper wing 3–10 mm wide, lower wing 2–5 mm wide, seed chamber absent. Seeds 1 per fruit or sometimes immature, discoid, flat, 13–14 x 12–13 x 1–2 mm; hilum central, 1–1.4 mm long.