Derris trifoliata Lour.

        Lianas, sometimes more or less creeping, up to 8 m long, up to 5 cm diam. Twigs hollow, 4–7 mm diam., glabrous, lenticellate. Leaves with 3–7 leaflets, rarely unifoliolate. Stipules triangular, 1.5–2 x ca. 2 mm, glabrous, caducous. Petiole 1.5–10 cm long, grooved above, striate, glabrous; rachis 1.5–6 cm long, grooved above, striate, glabrous; pulvinus 3–10 mm long, glabrous. Stipellae sometimes present, acicular, 0.5–1(–1.5) mm long, glabrous. Leaflets subcoriaceous to coriaceous; terminal one ovate to elliptic, 3.5–16 x 1.5–8.5 cm, length/width ratio 1.8–3, base slightly cordate to (sub)peltate, rarely rounded, apex emarginate, rounded or acuminate, acumen 3–25 mm long, upper and lower surface glabrous, midrib and nerves flat or slightly raised, veins 5–11 per side, 3–20mm apart, not reaching the margin but curving towards the apex, anastomosing before the margin, venation reticulate; lateral ones mostly like the terminal one, narrowly elliptic to ovate, 2.5–12 x 1–5.5 cm, length/width ratio 1.7–3.6; pulvinus 4–7 mm long. Inflorescences axillary or ramiflorous (then often on creeping branches), pseudoracemes rarely pseudo-panicles, 1–18 cm long, peduncle 0.2–4.5 cm long, thinly strigose. Bracts subtending brachyblasts triangular, 0.6 –1.4 x 0.5–1 mm, outside glabrous or thinly sericeous, margin ciliate, inside glabrous. Brachyblasts knob-like, up to 5 mm long, with 2 or 3(–7) flowers. Bracts subtending flowers elliptic to triangular, orbicular or cordate, 0.5–0.8 x 0.3–0.6 mm, both sides glabrous, margin ciliate. Pedicels 2–6 mm long, glabrous or with few hairs. Bracteoles at the apex or the upper part of the pedicels, elliptic, triangular, orbicular or cordate, 0.5–0.7 x 0.4–0.6 mm, both sides glabrous, margin ciliate. Calyx cup-shaped, 2.5–4 mm long, outside glabrous, teeth ciliate, inside sericeous in upper part, tube 2–3 mm long; upper lip usually shallowly notched, 0.25–0.5 x 2.5–4 mm; lateral lobes triangular or semi-circular, ca. 0.5 x 1–2 mm; lower lobe triangular, ca. 0.5 x 1.5–2 mm. Corolla white to pale pink. Standard with a green spot at the base; claw 2–3 mm long; blade orbicular, 7–9.5 x 7.5–10 mm, apex slightly emarginate, basal callosities absent, both sides glabrous. Wings: claw 2.5–4 mm long; blade elliptic, 6–9 x 2–3 mm, apex rounded, both sides glabrous, lateral pocket indistinct, upper auricle 0.5–1 mm long. Keel petals: claw 2.5–3.5 mm long; blade boat-shaped, 6–8 x 3–4 mm, apex rounded, both sides glabrous, lateral pocket ca. 2 mm long, upper auricle indistinct or sometimes up to 1 mm long. Stamens monadelphous, with basal fenestrae, 8–12 mm long, free part 1.5–4 mm long, glabrous; anthers 0.6–0.8 x 0.3–0.5 mm, glabrous. Disc absent. Ovary 3–5 mm long, stipe indistinct, sericeous; ovules 3–8; style 6–9 mm long, glabrous or sometimes sericeous for up to 2/3. Pods elliptic to more or less discoid or obovoid, 30–55 x 20–37 mm, with few hairs especially basally and on the beak, upper wing only, 1–5 mm wide; seed chamber absent. Seeds 1–3 per fruit, flat, bean-shaped, 13–23 x 12–21 x 2–5 mm; hilum central, ca. 1 mm long.