322 HIPPOCASTANE^. [part ii. 



the Ash, and its long pea-green shoots, which 

 have very few buds. The male and female 

 flowers of the Negundo are on different trees, 

 and they are so small as to be seldom seen, 

 though the racemes of samaras or keys which 

 succeed the flowers are very conspicuous. The 

 Negundo is a native of America, and its leaves 

 turn yellow in autumn. 



ORDER XLV.— HTPPOCASTANE^, OR ^SCULACE^E. 

 THE HORSE-CHESTNUT TRIBE. 



This order contains only two genera ; viz., 

 iEsculus, the Horse-chestnut, and Pavia, the 

 Buckeye; both of which are generally called 

 Horse-chestnuts, though the genera are easily 

 distinguished by their fruit, the husk of which 

 is smooth in the Pavias, but rough in the true 

 Horse-chestnuts. The buds of all the species of 

 both genera are covered with bracted scales, 

 most of which fall off* when the leaves and 

 flowers expand; and those of the common Horse- 

 chestnut (y^sculus Hippocastanum) are very large, 

 and covered with a kind of gum. Four large 

 compound leaves, each consisting of five or seven 

 leaflets, and a raceme of sixty-eight flowers, have 

 been unfolded on dissecting one of these buds, 

 before the leaves unfold in spring. The flowers 

 of this species are produced in large, upright 



