Senna

a drug consisting of the dried leaflets of several kinds of cassia. One species, a pea-like herb, with yellow flowers and sensitive leaflets, grows wild in the United States. It is known to botanists under the name of cassia marilandica. The common name is partridge pea. American children touch the leaflets to see them close up like a sensitive plant. The drug, senna, is obtained, however, chiefly from an African species. It is exported from Alexandria. This is the leaf used to make senna tea, taken for medicinal purposes. See Sensitive Plant