IN recent years considerable interest has been aroused in the use of the alkaloid reserpine in the treatment of hypertension and various mental disorders. Various plants in the family of Apocynaceae other than Rauwolfia have been investigated, and among them the isolation of reserpine from Alstonia constricta 1 is noteworthy. With the view of detecting the presence of reserpine in the plants of the Apocynaceae family we have studied the plant Vinca rosea. Several alkaloids have been reported from this plant: vinceine (melting point, 259–260° C.)2, and vincaine (melting point, 250–252° C.)3, which appears to be identical or stereoisomeric with δ-yohimbine. According to Beereboom et al. 4, vinceine and vincaine are indeed identical with ajmalicine, and the same authors have reported4 the presence of serpentine (melting point, 156° C., with decomposition) and a new alkaloid, C20–21H26–28N2O2 (melting point, 200–201° C.) which they propose to name ‘lochnerine’. Recently, ursolic acid (melting point, 280° C.)5 has been reported present in Vinca rosea.