Albizia julibrissin Durazz. Fabaceae. Persian silk tree. Called 'shabkhosb' in Persian, meaning 'sleeping tree' as the pinnate leaves close up at night. Tropical tree. Named for Filippo degli Albizzi, an Italian naturalist, who brought seeds from Constantinople to Florence in 1749, and introduced it to European horticulture. The specific epithet comes from the Persian 'gul-i abrisham' which means 'silk flower'. Distribution: South Africa to Ethiopia, Senegal, Madagascar, Asia. Bark is poisonous and emetic and antihelminthic. Various preparations are widely used for numerous conditions and the oxitocic albitocin is abortifacient. However, studies on the seeds and bark of other Albizia species in Africa, demonstrate it is highly toxic, half a kilogram of seeds given to a quarter ton bull, killed it in two hours (Neuwinger, 1996). A useful tree for controlling soil erosion, producing shade in coffee plantations, and as a decorative shade tree in gardens. Photographed in the Medicinal Garden of the Royal College of Physicians, London.