APOCYNACEjE. 455 



Alexandrian Senna. The fragrant roots of ffemidesmus indicus axe 

 used in Madras as a substitute for Sarsaparilla, under the name of 

 Country Sarza. The bark of the root of several species of Calotropis, 

 such as C. procera, Hamiltonii, and gigantea, furnish the substance called 

 Mudar, which is used as a diaphoretic in India. It contains a principle 

 called Mudarine, which gelatinizes on being heated, and becomes fluid 

 on cooling. Cynanchum monspeliacum furnishes MontpeUier Scammony, 

 and Periploca mauritiana is the source of Bourbon Scammony. Both 

 of these substances act as purgatives, and are used to adulterate true 

 Scammony. Marsdenia tinctoria and Gymnema tingens are said to 

 yield a dye similar to indigo. The milky juice of many of the plants 

 contains caoutchouc in its composition. Hoya camosa receives the 

 name of wax-flower from the peculiar aspect of its blossoms. Dis- 

 chidia Itafflesiana, an Indian climber, has remarkable ascidia (^[ 164). 

 The Stapelias are singular plants, resembling some of the Cactuses and 

 Euphorbias. Their blossoms are often very fetid, and hence they are 

 called Carrion flowers. Some of the species of Asclepias receive the 

 name of Wild Cotton, on account of the hairs attached to their seeds. 

 Gomphocarpus fructicosus is the silk-plant of Madeira. 



944. Order 125. Apocynacete, the Dogbane Family. (Monopet. 

 Hypoy.) Calyx usually 5 -partite, persistent. Corolla hypogynous, 

 gamopetalous, regular, usually 5-lobed, deciduous ; aestivation con- 

 torted, twisting in some cases to the right, in others to the left. Sta- 

 mens 5, inserted on the corolla, alternate with its segments; filaments 

 distinct; anthers 2-celled, dehiscing longitudinally; pollen granular, 

 globose, or 3-lobed, immediately applied to the stigma. Ovaries 2, 

 and each unilocular, or uni-, and bilocular; ovules 00; styles 2 or 1; 

 stigma 1, with a contraction in the middle. Fruit follicular or capsu- 

 lar, or drupaceous or baccate, double or single. Seeds 00, rarely 

 definite, usually pendulous; albumen cartilaginous or fleshy, rarely 0; 

 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. 

 Examples Apocynum, Echites, Nerium, Balfouria, Vinca, Tanghinia, 

 Plumieria, Carissa. 



945. Many of the plants of this order are poisonous. Some are 

 used medicinally, as cathartics, and there are a few which yield edible 

 fruits. The order is in general to be regarded with suspicion. One 

 of the most deadly plants of the order is Tanghinia venenata (Cerbera 

 Tanghin), the seeds of which supply the famous Tanghin poison, used 

 formerly in Madagascar as an ordeal in cases of criminals. Nerium 

 Oleander, the common Oleander, is poisonous. The stomata of its 

 leaves are formed by means of cellular hair-like processes (fig. 76), 

 and the anthers are terminated by feathery appendages (fig. 334). 



