Indigofera tinctoria L.

Erect or spreading suffruticose shrub to c. 2 m high; young stems ridged, strigose with dense, appressed, equally biramous hairs. Leaves pinnate, 8.5–13 cm long, with 9–13 leaflets; stipules narrowly triangular, 1–3.5 mm long, pubescent; petiole 8–15 (–20) mm long; rachis slightly furrowed; leaflets opposite, discolorous, obovate, 10–25 (–35) mm long, 4–14 (–23) mm wide; apex obtuse and emarginate or mucronate. Inflorescences 1.5–9.5 cm long, shorter than leaves; peduncle 1–2 mm long; bracts triangular to subulate, 0.5–1.1 mm long; pedicel 0.7–1.2 mm long; flowers pink and greenish. Calyx 1.2–2.1 mm long; lobes triangular, about as long as the tube, clothed with moderately dense, grey, appressed hairs. Standard ovate to orbicular, 4–6.6 mm high, 2.8–5.2 mm wide. Wings narrowly obovate, (4–) 5–6 mm long, 1.2–2.1 mm wide. Keel 4.5–6.7 mm long, 1.2–1.7 mm deep; apex rounded; lateral pockets 0.8–1.1 mm long. Staminal tube 3.5–4.5 mm long, colourless. Ovary moderately hairy. Pods descending, terete and slightly torulose, usually slightly curved towards the tip, 23–35 mm long, 1.5–2 mm deep, brown, glabrescent; hairs sparse, appressed; apex shortly beaked; endocarp spotted. Seed 7–10 per fruit.

Disturbed places, tending to favour seasonally dry areas.

This species is of Asian origin and was widely exploited in tropical and subtropical parts of the Old World for indigo dye production.

Can be grown by cuttings or seedlings. Seeds needs soaking.