The dried bark of Alstonia scholaris (L.) R. Br. and of A. constricta F. Muell., Apocynaceae. Habit. India, Ceylon, Philippine Islands, Australia. Constit. The alkaloids echitamine, echitenine, alsonine, porphyrine; echicerin—a non-nitrogenous substance; echitin, alstonidine and echitein.