PLANTS. 241 



is the well known Gamboge, used by painters in Aqua- 

 relle, and is also of some importance in medicine as a 

 purgative. 



NINETEENTH FAMILY. HIPPOCASTANACE^:. BUCK- 

 EYE. (Class 7. L.) Are trees or shrubs with knotty 

 branches ; leaves acute, dentate, sometimes digitate. 



The Horse Chestnut (TEsculus hippocastanum) has 

 leaves compound digitate by sevens and fives flowers 

 arranged in tufts standing upright. This ornamental 

 tree, often from sixty to eighty feet in height, with its 

 dark leaves throwing a deep shadow and its white flow- 

 ers, spotted with red and tinged with yellow, presents in 

 spring a perfect specimen of rare and sylvan beauty. A 

 native of Thibet and Northern India, it was introduced 

 into Europe towards the close of the sixteenth century. 

 The seeds, of the same color as those of the common 

 chestnut, contain a farinaceous substance, but which can 

 not be used on account of its bitter taste. Horses refuse 

 to eat it, but sheep feed on it readily. The wood is used 

 by carpenters, and the bark by tanners, also occasionally 

 employed as medicine. ^ . 



ACERACE.E. MAPLES. The Sycamore (Acer pseu- 

 do-platanus) is a handsome tree ; the leaves are heart- 

 shaped and five-lobed ; grows to a height of more than 

 forty or fifty feet ; flowers greenish-yellow, hang in clus- 

 ters, and belong to the 23rd class of Linnaeus, as they 

 possess both pistil and stamen. The bark is smooth and 

 exfoliates in thin plates. The wood is white, and not 

 much esteemed ; is occasionally sawed into joists and 

 other lumber. i> 



Sugar or Rock Maple (Acer saccharinum), found 

 throughout the United States, is a tree of lofty propor- 

 tions, often seventy feet in height, with a trunk three 

 11 



