Robinia pseudoacacia L.

Trees, 10-25 m tall, deciduous. Bark gray-brown to dark brown, longitudinally fissured, rarely smooth. Branchlets gray-brown, sparsely hairy, glabrescent; stipulate spines up to 2 cm; winter buds small, with hairs. Leaves 10-25(-40) cm; rachis adaxially grooved; petiolule 1-3 mm; stipel acicular; leaflets 2-12 pairs, usually opposite or subopposite; leaflet blades oblong, elliptic, or ovate, 2-5 × 1.5-2.2 cm, abaxially grayish green and with appressed pubescence when young but glabrescent, adax­ially green, base rounded to broadly cuneate, margin entire, apex rounded, retuse, and apiculate. Racemes axillary, 10-20 cm, pendulous, many flowered, fragrant; bracts caducous. Pedi­cel 7-8 mm. Calyx obliquely campanulate, 7-9 mm; teeth 5, triangular to ovate-triangular, densely appressed pubescent. Co­rolla white, stipitate; standard suborbicular, ca. 1.6 × 1.9 cm, re­flexed, inside with yellow spots, base rounded, apex with a sinus; wings obliquely obovate, subequal to standard, ca. 16 mm, one lateral auriculate rounded; keel falcate, triangular, equal to wings or slightly short, connate at leading edge, obtuse. Stamens diadelphous, one opposite to standard free. Ovary line­ar, ca. 1.2 cm, glabrous; stalk 2-3 mm; style subulate, ca. 8 mm, apically curved, apex piliferous; stigma terminal. Legume brown or with reddish brown stripes, linear-oblong, 5-12 × 1-1.3(-1.7) cm, compressed, apex volute and mucronate, carpo­podium short, narrow wings along ventral suture; calyx persis­tent, 2-15-seeded. Seeds brown to dark brown, slightly glossy, sometimes with stripes, subreniform, 5-6 × ca. 3 mm; hilum rounded, oblique to one end. Fl. Apr-Jun, fr. Aug-Sep. 2n = 20, 22.

It is a temperate plant. It is native to S.E. United States. It grows in well drained temperate woodlands. It is frost hardy. It thrives on limestone soils. It can grow in alkaline soils. It cannot tolerate shade. It grows in areas with an annual rainfall between 510-1,400 mm. It can grow in arid places. It suits hardiness zones 3-10. Mt Cootha Botanical Gardens. Hobart Botanical Gardens. In Sichuan. In Yunnan. Arboretum Tasmania.

The flowers are sweet and edible. They are dipped in butter and fried. They are used to make a sweet tea. The leaves are used fresh or dried for tea. The flowers yield an oil used in flavouring. The young pods are cooked as a vegetable. The seeds are boiled and eaten.

The seeds have a hard seed coat. They can last in the soil for 10 years. Plants can be grown from root sprouts.