Robinia pseudoacacia, commonly known in its native territory as black locust, is a medium-sized hardwood deciduous tree endemic to a few small areas of the United States, but it has been widely planted and naturalized elsewhere in temperate North America, Europe, Southern Africa and Asia and is considered an invasive species in some areas. Another common name is false acacia, a literal translation of the specific name (pseudo meaning fake or false and acacia referring to the genus of plants with the same name.) It was introduced into Britain in 1636.
Large tree 20-25 (35) m high. Crohn's lace, sprawling, widely cylindrical. The diameter of the trunk sometimes reaches 1 meter. Young shoots are initially slightly pubescent, then bare, from olive-green to brilliant reddish-brown shades, in older plants, thick cracking bark of gray-brown color, with deep longitudinal cracks. The root system is powerful, core, branching (12-15 m in diameter). The roots contain many sclerenchymic elements. A remarkable feature of the roots is the symbiotic relationship with nitrogen-fixing (nodule) bacteria, which grow to form nodules, thanks to which the plant can develop well even on soils poor in nitrogen. The leaves are alternate, complex, pinnate with 9-17 oval or oblong leaflets, with stipules modified into thorns. The flowers are white, fragrant, bisexual, zygomorphic, with a double perianth in racemose inflorescences collected in a common panicle. Calyx is leafy, two-lipped. The moth corolla consists of a flag, or a sail, two wings, or oars, and a boat formed by two fused petals and covering the stamens (10, of which 9 are fused with stamens and 1 free) and a pistil formed from one carpel. At the base of the petals are nectar-bearing glands. Ovary upper. Formula of white acacia flower: Ch3L1,2 (2) T (5 + 4) 1P1. Fruit - a bean with a short peduncle, oblong-linear in shape, oblate, bivalve, multi-seeded, brown. It blooms at the age of six at the beginning of summer (May - July). Fruits in autumn in late September, often acacia beans hang on trees until the end of winter.