senna

Any of several plants, especially of the genus Cassia, in the pea family (see legume), mostly of subtropical and tropical regions. Many are used medicinally; some yield tanbark used in preparing leather. Some sennas are among the showiest flowering trees. In the eastern U.S., wild sennas (C. hebecarpa and C. marilandica) grow up to 4 ft (1.25 m) high and have showy spikes of yellow flowers. Some species are Old World shrubs or small trees.

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