This member of the Legume subfamily, Faboideae, is native to central and southern Europe. We saw this specimen in an urban park in Bucharest, Romania on May 2, 2014. The compound leaves were distinctive in the form of three leaflets. The black seeds found in the pods (see photo below) contain the alkaloid cytisine, which is related to nicotine. In heavy doses, it can cause breathing problems and eventually death. Several genera of the Faboidea sub-family have this alkaloid. It was used as a smoking cessation drug in Eastern Europe during the socialist era.
It is a small tree and common in parks and gardens because of its hardiness and its stunning chains of bright yellow flowers. There are two species in the genus, another is found at higher elevations.