Senna leaves, known as Ajana leaves, senna leaves and bamboo leaves, derived from the small leaves of the leguminous plant senna with narrow leaves or senna with pointed leaves. Narrow leaf senna long ovate or ovate-lanceolate, 1.5 -- 5 x 0.4 -- 2cm, apically acute, base slightly asymmetrical, entire. Upper surface yellowish-green, lower surface light yellowish-green, glabrous or subglabrous, veins slightly raised. Quality. Gas is weak and specific, taste slightly bitter, slightly sticky. Apical senna lanceolate or long ovate, slightly curled, apiculate or puberulent at the tip, asymmetrical at the base, with fine short hairs on both sides.Storage method of senna leaves: keep in a cool and dry place, away from light and high temperature. 2. The time of senna leaf soaking in water should not be too short, it is best to soak for about 25 minutes, so as to better play the role of diarrhea, wait for the water to cool before drinking. Can be repeated brewing, the second time is generally added about 150 ml of water, usually can be soaked twice. 1. First, put about 2-3 grams of senna leaves in a teacup and add about 200 ml of boiling water. If the constitution is strong, you can appropriately increase the amount of senna leaf, such as 6 grams a time, normal or weak people with 2 to 3 grams. The correct way to soak senna leaves is to soak 2 to 3 grams of senna leaves in 200 milliliters of water for 25 minutes before the water cools.