602 A TEXT-BOOK OF BOTANY. 



the East Indies. The yellow coloring principle in the arils of the 

 seeds of Celastrus and Euonymus appears to closely resemble 

 carotin. The seeds of a number of plants of this family contain 

 a considerable quantity of fixed oil, as Celastrus macrocarpus of 

 Peru, and Maytenus Boaria of Chile. 



/. ACERACE^: OR MAPLE FAMILY. The plants of this 

 family are trees or shrubs, the most widely distributed repre- 

 sentative of which is the maple (Acer). The most distinguishing 

 character of this family is the fruit, which is a double samara. 

 The sap of a number of species of Acer contains cane sugar or 

 sucrose, and the sap of the sugar maple (Acer saccharinum) which 

 grows in the United States and Canada contains from 3 to 4 per 

 cent. The making of maple syrup and maple sugar is quite an 

 industry in some localities. Maple sugar is also obtained from 

 the black sugar maple (Acer nigruni) and the ash-leaved maple 

 (A. Negundo). The bark of the latter species is used to some 

 extent in medicine. Valuable timber is yielded by the maple trees. 



g. HIPPOCASTANACE;E OR BUCKEYE FAMILY. 



The plants are shrubs or trees with opposite, petiolate, and 3- to 

 9-digitately-foliate leaves. The flowers are in terminal panicles 

 and the fruit is a 3-lobed capsule, which usually contains one 

 large, shiny seed. 



The horse-chestnut (JEsculus Hippocastanum') contains in the 

 bark two fluorescent .bitter principles, aesculin and paviin, the 

 former of which is in the nature of a glucoside ; and in the bark, 

 leaves and flowers the coloring principle, quercitrin is present; 



! in the seed-coat saponin is supposed to occur, and the glucoside 

 aesculin as well. The cotyledons contain considerable starch, some 

 proteins and sugar, a small quantity of a fixed oil, and argyresin, 



to which the antihemorrhoidal action appears to be due. A 

 narcotic principle is present in the bark, twigs and leaves of the 

 red buckeye (Aisculus Pavia) of the Southern United States. 



h. SAPINDACE;E OR SOAPBERRY FAMILY. The 



plants are mostly trees or shrubs indigenous to the Tropics. In 

 some genera they are herbaceous or woody vines (lianes). The 

 plants of this family usually have either a milky sap or contain 

 saponin, and it seems strange that a plant yielding caffeine, namely, 



