478 



HUTCHINSON'S POPULAR BOTANY 



FIGS. 586, 587, AND 585. 



are sometimes described as capsules are the follicle, the legume, the siliqua, 

 and the silicula. We will take them in that order. 



The follicle is a superior, one-celled fruit, containing one or more seeds. 

 which are liberated in most instances by a ventral suture only. Magnolia 

 glauca and some other species of Magnolia are exceptions. As a rule, 

 several follicles are collected in a cluster at the end of a flower-stalk, but 

 solitary follicles are common in Proteacese; and there are a few plants 

 (e.g. the Pseony, normally developing two or more follicles with each flower, 

 which occasionally produce but one. The Columbine (Aquilegia) and Lark- 

 spur (Delphinium) offer good examples of the follicle. 



The legume or pod resembles the follicle in that it arises from a single 

 carpel ; but, unlike the follicle, it dehisces at both sutures. This is the 

 characteristic fruit of the great order Leguminosece, to which the Pea 

 and Bean belong. The legumes assume a curious twisted form in the 

 small genus Scorpiurus, which includes the interesting Caterpillar-plant 

 (8. vermiculata, fig. 594), and a spiral form in the Purple Lucerne (Medicago 

 sativa, fig. 597). When the pod is contracted in a bead-like (moniliform 

 manner, as in the Gum Arabic plant (Acacia arabica, fig. 601), it is termed 



a lomentum. 



The legumes of the Earth-nut (Arachis 

 hypogcea, fig. 599) deserve notice on account of 

 peculiarities other than those of form. The 

 specific name hypogcea (Greek upo ge, under 

 ground) is an allusion to the curious circum- 

 stance that the young pods, as they begin to 

 mature, are forced into the earth by a lengthen- 

 ing of the flower-stalks, and ripen their seeds 

 -^^_r_ ^ below the ground. This phenomenon is not 



\ confined to the Earth-nut, but has been ob- 



served in a few other plants Trifolium subter- 

 raneum, for example, and the Sweet Violet 

 (Viola odorata). The fruits of the latter are 

 completely," like a iid. not leguminous. Plants with burying fruits, 



FIG. 589. PIMPERNEL. 



The fruit is a pyxidium, which splits trans- 

 versely and the upper part falls away 



