(also known as senna), a genus of perennial herbs, shrubs, or small trees of the family Leguminosae. The leaves are compound, even-pinnate, with five to ten pairs of narrow leaflets. The flowers are yellow (more rarely, white or reddish) and are gathered into racemes. Although they are irregular, their petals are almost identical in size. There are ten stamens—three are often reduced. There are approximately 500–600 species, distributed primarily in the tropics and subtropics of both hemispheres (particularly in America).
Several species are used in medicine, including Cassia angus-tifolia (native to western Arabia), C. acutifolia (native to mountainous regions of the Sudan, cultivated in the USSR in Middle Asia and Kazakhstan), and C. obovata (native to Sudan; cultivated in Transcaucasia, Krasnodar Krai, and the southern Ukraine). They are the source of Alexandrian leaf. Senna leaves, the leaves of C. acutifolia, contain anthraglycosides, which act as a cathartic when taken internally. They are used in the form of an infusion, as a cathartic tea (black draft). Senna leaves are a component of the complex powder of licorice root. In the USSR, C. angustifolia and C. acutifolia are cultivated as annuals on irrigated lands in southern Kazakhstan and Middle Asia.
In order to develop normally, cassia needs a sunny exposureand warmth. It grows best in loose nonsaline, loamy soils withdeep ground water. Cassia should be planted in soil from whichpasture crops have been harvested. Before planting, immediatefall plowing is done, with preliminary irrigation. During plow-ing, manure (20–30 tons per hectare) or compost with super-phosphate (3 centners/ha) is applied. Early in spring the field isharrowed, and the soil is leveled. The field is sown (8 kg/ha); thewidth between the rows of seeds is 60–70 cm. During the periodof growth and development (the phase of blooming and branch-ing), the plants are fed ammonium sulfate and superphosphateand irrigated five or six times. When a yellowish tint appears onthe lower leaves, harvesting is begun. The second, or principal, gathering of leaves occurs after 20–25 days. The leaves are driedin shade or sun. The yield of air-dried leaves and fruits is 8–10centners/ha.