The New International Encyclopædia/Apocynaceæ
AP'OCYNA'CEÆ (Gk. ἀπό, apo, away from, + κύων, kyōn, dog). The Dogbane Family. An order of dicotyledonous plants, the species of which are herbs, shrubs, vines, and trees, mostly with a copious, milky juice. The leaves are mostly opposite, entire, and without stipules. The flowers are five-parted; ovary single and two-celled, or two and cone-celled. Fruit, a follicle or drupe; seeds with a straight embryo; endosperm small or none; seed often covered with a thistle-like down. There are about 130 genera and more than 1000 species in this order, the principal subdivisions of which are: Arduineæ, represented by Arduina and Laedolphia; Plumerieæ, containing the tropical genus Tabernæmontana, and Aspidiosperma, Vinca, and Alstonia; and Echitideæ, which embraces Kickxia, Apocynum, Nerium, and Strophanthus. The properties of plants of this order vary greatly, but many are exceedingly poisonous. Some, like Kickxia and Landolphia, are rich in caoutchoue; Apocynum yields valuable bast fibre, and its rhizomes are used in medicine; Strophanthus contains in its seed a powerful poisonous alkaloid; while others have varied economic uses. See Periwinkle; Oleander; Indian Hemp; Rubber; Strophanthus; Dogbane; Wrightia; Poisonous Plants, etc.