(broom), a genus of deciduous and, less commonly, evergreen plants of the family Leguminosae. The plants are low shrubs or, rarely, small trees, measuring up to 3 m tall and sometimes having small thorns. The leaves are ternate or, less commonly, entire. The flowers are yellow or white and are gathered into axillary racemes or terminal heads. Purple and pink flowers are occasionally encountered. All the stamens are fused. The elongate pods are dehiscent and one-, two-, or many-seeded. The seeds are kidney-shaped and flat and have an aril.
The genus Cytisus has about 30 species (according to some data, as many as 60), distributed in Southern Europe, Central Europe, Western Siberia, and Northwest Africa. The USSR has about 20 species, which grow in steppes and forests, on rocky and limestone slopes, and on riverbank sands. The most widespread species is C. ruthenicus. The plants yield a substantial amount of nectar. Some species are raised as ornamentals. Many are poisonous, since they contain the alkaloid cytisine, which raises blood pressure and stimulates respiration.