272 The Natural System of Botany. 



THE NATURAL SYSTEM OF BOTANY. 



H CM B K K NISI* 



Order — Aceraceje. The Maple Tribe. 



This order contains some of the finest forest trees of northern 

 countries. Several species of Maple are among the most com- 

 mon and useful. Of these the wood is extensively used in th e 

 manufacture of furniture, and for other useful purposes, and 

 the sap of the sugar maple affords a well known and very 

 pleasant saccharine substance. The characters of the order 

 are easily ascertained. The leaves aro opposite, and without 

 stipules; the flowers are small, regular, sometimes perfect, and 

 often dioecious or polygamous. The calyx has five sepals, and 

 the corolla, when present, the same number of petals. The 

 fruit is always a Samara, or ovary expanding into wings. 

 The shape and appearance of this is well observed in the com- 

 mon white or red maple. 



Order — Hippocastaneje. The Horse- Chestnut Tribe. 



The species belonging to this order are ornamental 

 The common Horse-Chestnut, so generally admired for the 

 richness of its foliage, the beauty of its flowers, and the ele- 

 gance of its whole aspect, is a native of the north of Asia, 

 The characteristics of the order are readily observed in this 

 fine tree. The leaves are digitate, without stipules ; the flow- 

 ers are showy, in a large panicle ; the calyx has five united 

 sepals ; the corolla is irregular, with five petals ; the stamens 

 are from six to eight, usually seven, unequal in length; the 

 fruit is roundish, with a leathery envelope, enclosing one or two 

 large, smooth, roundish seeds, which contain much bitter, 

 starchy matter. 



* 



Order — CelastracejE. The Staff- Tree Tribe. 



These are shrubs or small trees, and arc possessed of a bit- 

 ter or acid principle, which, however, does not appear to be 



