THE FRUIT 



223 



a seed which springs from a single ovule of one cell of a 

 compound ovary, which develops at the expense of all the 

 other ovules. The chestnut-bur is a kind of involucre, 

 and so is the acorn-cup. The name 

 nut is often incorrectly applied in 

 popular language; for example, the 

 so-called Brazil-nut is really a large 

 seed with a very hard testa. 



238. The Follicle. One-celled, 

 simple pistils, like those of the marsh 

 marigold, the columbine, and a good 

 many other plants, often produce a 

 FIG. IBS. -Group of Fom- fruit which dehisces along a single 

 cies and a single Foiiicie suture , usually the ventral one. Such 



of the Monkshood. J 



a fruit is called a follicle (Fig. 168). 



239. The Legume. A legume is a one-celled pod, 

 formed by the maturing of a simple pistil, which dehisces 

 along both of its sutures, as already seen in the case of 

 the bean pod, and illus- 

 trated in Fig. 271. 



240. The Capsule. 

 The dehiscent fruit 

 formed by the ripening 

 of a compound pistil is 

 called a capsule. Such 

 a fruit may be one- 

 celled, as in the linear 

 pod of the celandine 

 (Fig. 271), or several- 

 celled, as in the fruit of the poppy, the morning-glory, 

 and the jimson weed (Fig. 271). 



FIG. 169. Winged Fruits. 

 I, elm ; H, maple. 



