124 BOTANY. 



to the stigma. Ovaries two, and each unilocular, or one and bilocular ; 

 ovules 00; styles two or one; stigma one, with a contraction in the middle. 

 Fruit follicular or capsular, or drupaceous or baccate, double or single. 

 Seeds 00, rarely definite, usually pendulous ; albumen cartilaginous, or 

 fleshy, rarely ; embryo foliaceous ; radicle turned towards the hilum. 

 Trees or shrubs, usually lactescent, with entire, generally opposite, 

 exstipulate leaves, with interpetiolary cilia or glands. They are chiefly 

 found in tropical regions. Lindley enumerates 100 genera, including 566 

 species. 



Sub-orde?' 1. CarissecB. Ovary single, bilocular, or unilocular, with 

 placentas parietal and corresponding to the suture of the carpels. Fruit 

 baccate, very rarely capsular. Example : Carissa. 



Sub-order 2. Opkioxylece. Ovary double, fruit drupaceous. Examples : 

 Ophioxylon, Cerbera. 



Sub-order 3. Euapocyanece. Ovary double. Fruit follicular ; follicles 

 often fleshy or pulpy. Tribe 1. Plumeriece. Seeds without hairs, often 

 peltate. Examples : Hunteria, Tabernaemontana, &c. Tribe 2. AlstoniecB. 

 Follicles coriaceous ; seeds peltate, ciliate ; ciliae elongated, forming a kind 

 of coma at the two ends of the seeds. Example : Alstonia. Tribe 3. 

 Echitece. Follicles coriaceous or membranous, distinct or rarely united so 

 as to constitute a single capsule. Seeds comatose towards the hilum or 

 point of attachment. Examples : Apocynum, Nerium. 



Sub-order 4. Wrightiece. Seeds comatose at the apex. Example : 

 Wrightia. 



The sole representative of this order in the northern part of North 

 America is the genus Apocynum or dogbane, supposed to be poisonous to 

 dogs. Many plants of the order are poisonous, although a few yield edible 

 fruits. The Tanghin poison of Madagascar is obtained from the seeds of 

 Tanginia venenata. Even the common Oleander (Nerium) is poisonous. 

 Species of Urceola and Vahea supply caoutchouc. The juice of Taber- 

 naemontana utilis, the Cow tree of Demerara, is used as milk. 



Nerium oleander, Oleander (Europe and Asia) {pi. 63, fig. 13) ; a, 

 anther ; b, pistil ; c, a seed. 



Order 99. Asclepiadace.e, the Milkweed Family. Calyx five-divided, 

 persistent. Corolla synpetalous (monopetalous), hypogynous, regular, five- 

 lobed, deciduous; aestivation imbricate, rarely valvate. Stamens five, 

 inserted into the base of the corolla, and alternate with its segments ; 

 filaments usually combined so as to form a tube ; staminal tube rarely naked 

 behind, generally furnished with a corona (crown) of variously-formed 

 leaves, which are either distinct or connate. Anthers bilocular, each cell 

 sometimes spuriously divided ; pollen, when the anther dehisces, cohering 

 in masses (pollinia), which are either as numerous as the cells, or are 

 confluent in pairs, and adhere to the five stigmatic processes, either in sets 

 of two or four, or singly. Ovaries two ; ovules 00 ; styles two, closely 

 approaching each other, often very short ; stigma common in both styles, 

 dilated, quinquangular ; the angles furnished with cartilaginous corpuscles 

 which retain the pollinia, or with glands. Fruit consisting of two follicles 

 124 



