dogbane family - chiefly tropical trees or shrubs or herbs having milky juice and often showy flowers; many are sources of drugsAlstonia, genus Alstonia - genus of evergreen trees or shrubs with white funnel-shaped flowers and milky sap; tropical Africa to southeastern Asia and Polynesia Amsonia, genus Amsonia - genus of herbs and subshrubs with milky juice and showy bluish flowers; Europe to Asia Minor to Japan and North America genus Carissa - Old World genus of tropical evergreen usually spiny shrubs Catharanthus, genus Catharanthus - small genus of erect annual or perennial herbs native to Madagascar; widely naturalized in the tropics; formerly included in genus Vinca genus Plumeria, Plumeria, Plumiera - deciduous shrubs and trees of tropical America having branches like candelabra and fragrant white or pink flowers genus Strophanthus - genus of tropical Asiatic and African shrubs and woody vines and small trees genus Thevetia, Thevetia - genus of poisonous tropical American evergreen shrubs and trees having entire leaves and large cymose flowers Gentianales, order Gentianales - an order of dicotyledonous plants having gamopetalous flowers; Gentianaceae; Apocynaceae; Asclepiadaceae; Loganiaceae; Oleaceae; Salvadoraceae |