180 
ORDER DECANDRIA. 
Tlie orders in the class Diadelphia, like those of the preceding 
class, are founded upon the number of stamens. 
Order Pent- Octandria. 
We could not expect from the character of the class, "stamens 
united into two sets," to find any plants with but one stamen. Those 
with five or eight stamens are all placed in one order called Pent- ^ 
octandria, (five and eight stamens ;) here we find the Corydalis, an. ' 
elegant plant with bulbous roots ; the corolla is rather ringent than 
papihonaceous. Fumaria is nearly allied to Corydalis by natural 
characters. In some cases the stamens have very broad bases, and 
scarcely seem united in this class. We find here Polygala, one 
species of which is called Seneca snake-root ; this not only pro- 
duces a beautiful flower, but is valuable in medicine. We have 
many species of this genus in our woods and meadows. 
Order Decandria. — Leguminous Plants. 
The tenth Order is wholly composed of plants with leguminous 
pods ; the general character of these plants is, a calyx, often 5-part- ' 
ed, corolla 5-petalled, inseited on the calyx, and consisting of a ban- 
ner, two wings and a keel ; stamens generally 10, mostly united into': 
two sets, 9 and 1 ; germ free ; style 1 ; legume generally 2-valved, 1- ■ 
celled, sometimes transversely divided into many cells j seeds atfixed ' 
to the edge on one side. 
At Fig. 141, a, is a flower of this kind; b, shows the stamens di 
vested of their petals ; c, shows the pistil, the germ already exhibit- 
ing the form and appearance of the legume. 
In this large family of plants with leguminous pods are Uxany 
genera of great importance in the vegetable kingdom ; but when 
we are able to give striking natural characters, there seems to be 
less need of particularizing each genus. The form of the corolla 
and the nature of the fruit, with few exceptions, settle the characters 
of this class. 
The most savage nations usually pay some attention to Diadel 
phous plants. When Ferdinand de Soto marched his army into ' 
Florida, before the middle of the 16th century, he found the grana-' 
ries of the natives " well stored with Indian corn and certain tegu- 
minous seeds which were probably the Lima bean, {DulicJws^) or 
some species of that genus, for the natives still continue to culti- 
vate them. 
The bean and pea tribes are found here. They consist of several 
different genera, as the vetch plants, Vicia, in which are maiiy cul-; 
tivated species, and the indigenous one, Americana. The Phabeolus,.; 
or kidney-bean, has its native as well as exotic species. The pea,., 
so much valued as a table vegetable, belongs to the genus Pisum, a, 
species of which, called Beach-pea, is found upon the shores of lakes 
and the sea-coast. The rattle-box {CTotolaria) with its inflated per- 
icarp, is a favourite with children, who find it on sandy plains ; it is 
a low pubescent plant with yellow blossoms. Of clover ( Trifolium) 
there are many species, as the red, yellow, white, &c. The locust, 
tribe contains many ornamental shrubs and trees. 
The indigo {Indigofera tinctoria) of warmer chmates, the red' 
sandal-wood of the East Indies, the liquorice, and the sensitive plant, 
are all of this class. The gum-arabic is obtained from the acacia-; 
of the Nile, {Mimosa nilotica.) The liquorice of commerce is ob-^'^ 
Order Peni-Octandria— Corydalis— Polygala— Order Decandria— General character 
of plants of this order— Savages culiivate tiiese plains— Bean and pea inbe— Indigo, 
