474 ` THE ROYAL FAMILIES OF PLANTS. 
odd sepal will always be found at top, or next the stem. 
The invariability of these facts is really wonderful. It is 
one of those great little things whose discovery sheds 
such lustre on the genius of Robert Brown, the man 
whose eye pierced more keenly through the vegetable 
millstone, than any other man’s before or since his time. 
Recapitulate then. The marks of the Pisids are,— 
1. Butterfly, or better, pea-flowers. 
2. Legumes, or simple pods, for fruit. 
3. The odd sepal turned away from the stem. 
True, these are not all the marks that are useful in dis- 
tinguishing this family. But they are the most simple 
and certain at once. Almost all have compound leaves, 
such as are found on the Locust, Clover, and Acacia. 
But we cannot be entirely safe in depending on this; for, 
not to speak of exotics, the Woodwaxen contradicts the 
point at our very door. But the Woodwaxen has the 
three great marks all very plainly, and therefore is a true 
Pisid, belonging or to the royal line, hate it as we 
will. 
In this great family there are three sets, or, as We 
might say, cousinships. They are each marked by some 
distinctive properties, and each varies in certain degrees 
and manners from the typical structure which belongs to 
First. We have a set with perfect pea-flowers and 
mostly true pods; but in some, as the Tonka-bean, 
and the Ground-plum of the West, the pod grows thick 
and fleshy, and closely resembles a drupe, or stone-fruit 
of some sort. In this tribe we meet with nearly all the 
‘Species that afford valuable food to man or beast. We 
| — need to cite examples. 
Second. We finda set with flowers quite indefinite in 
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