224 CLASS HEPTANDRIA, 



the more agreeable to us as we have so few trees whose flowers 

 are conspicuous. The blossom is very irregular in its parts, 

 that is, its number of other divisions do not correspond with 

 the usual number of stamens ; the stamens, however, vary as 

 to number. The seeds in form have a resemblance to ches- 

 nuts, but their taste is bitter. A very large species, the pallida, 

 having pale flowers, is a native of the southern and western 

 states. The horse-chesnut exhibits in its buds, in a very con- 

 spicuous manner, the woolly envelope which surrounds the 

 young flowers, the scales which cover this envelope, and the 

 varnish which covers the whole. The wood of this tree 

 affords a good subject for studying the formation and growth 

 of woody or exogenous stems. 



Tetragynia. 



There is but one plant with four pistils known in the class 

 Heptandria ; this alone constitutes the fourth order ; its com- 

 mon name is lizard's tail (Saururus)-, it has arrow shaped leaves, 

 flowers destitute of a corolla, and growing upon a spike ; it is 

 to be found in stagnant waters. 



Heptagynia. 



The septas, a native of the Cape of Good Hope, is considered 

 as the most perfect plant in this class ; it has 7 stamens, 7 pis- 

 tils, 7 petals, a calyx 7 parted, and 7 germs (one to each pistil), 

 which germs become 7 capsules, or seed vessels. 



Heptandria is the smallest of all the classes ; we do not find 

 here, as in most of the other classes, any natural families of 

 plants ; but the few genera which it contains not only differ in 

 natural characters from other plants, but seem to have no 

 general points of resemblance among themselves. 



Tetragynia Order Heptagynia Remarks upon the class Heptandria. 



