310 SIMPLE FRUITS— LEGUME. 
of simple fruits :—namely, the Legume, the Lomentum, the 
Drupe, and the Utricle. 
1. Legume or Pod—This is a superior, one-celled, one or 
many-seeded fruit, dehiscing by both ventral and dorsal sutures, 
so as to form two valves, and bearing its seed or seeds on the 
ventral suture. Examples occur in the Pea (jig. 668), Bean, 
Clover, and most plants of the order Leguminosez, which has 
derived its name from this circumstance. The lezume assumes 
a variety of forms, but it is generally more or less convex on 
its two surfaces and nearly straight ; at other times, however, it 
becomes spirally contorted so as to resemble a screw (jig. 691), or 
a snail twisted, asin some species of Medicago (fig. 690) ; or it is 
coiled up like a caterpillar, as in Scorpiwrus sulcata (fig. 689) ; 
Fie. 689. Fia. 691. Fie. 692. 
Fig. 689. Coiled-up legume of Scorpiurus sulcata. Fig. 690. Snail-like 
legume of Medicago orbiculata. Fig. 691. Spiral or screw-like legume of 
Lucerne (Medicago ).—Fig. 692. Lomentum of a species of Acacia. 
or curved like a worm, as in Cesalpinia coriaria ; or it assumes 
a number of other irregular forms. Certain deviations from 
the ordinary structure of a legume are met with in some 
plants ; thus, in Astragalus (fig. 619), and Phaca (fig. 620), it 
is two-celled, in consequence of the formation of a spurious 
dissepiment, which in the first plant proceeds from the dorsal 
suture, and in the latter from the ventral. (See page 277.) 
At other times a number of spurious horizontal dissepiments 
are formed, by which the legume becomes divided into as many 
cells as there are seeds, as in Cassia Fistula (fig. 614). Another 
irregularity also occurs in the latter plant, the legume being 
here indehiscent, but the two sutures are clearly marked ex- 
ternally. Other indehiscent legumes are also met with, as in 
Arachis and Pterocarpus, in which there is sometimes no 
evident mark of the sutures externally ; such legumes will, 
however, frequently split into two valves like those of a pea, 
