CULTIVATION AND HARVESTING The plants prefer rich, moist soil and much sun, and are often grown in succession to wheat and barley. Nearly all parts of the plant contain a white milky juice/latex but the unripe capsules are used for extraction of morphine and other alkaloids. Minor alkaloids are extracted from the straw also. The capsule wall is traversed by a network of branching and anastomosing lactiferous vessels which contain the latex. In the green unripe capsule , the latex is richest in morphine ; but as