186 



ELEMENTS OF BOTANY. 



Fig. 170. — Chestnut, a 

 Single Fruit. 



they never open, are usually taken by those who are not 



botanists for seeds. 



In the group of plants to which the daisy, the sunflower 



and the dandelion belong, the akenes consist of the ovary and 

 the adherent calyx-tube. The limb of the 

 calyx is borne on the summit of many 

 akenes, sometimes in the form of teeth, 

 sometimes as a tuft of hairs or bristles, 

 Fig. 174. 



220. The Grrain. — Grains, such as 

 corn, wheat, oats, barley, rice and so on 

 have the interior of the ovary completely 

 filled by the seed, and the seed-coats and 

 the wall of the ovary are firmly united, as 



shown in Fig. 9. 



221. The Nut. — A nut, Fig. 170, is larger than an akene, 

 usually has a harder shell and commonly contains 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 incor- 

 rectly applied in popular language, 

 for example, the so-called Brazil-nut 

 is really a large seed with a very 

 hard testa. 



222. Indehiscent and Dehiscent 

 Fruits. — All of the fruits so far 

 considered in the present chapter are 

 indehiscent, that is, they remain closed after ripening. Dehis- 

 cent fruits when ripe open in order to discharge their seeds. The 

 three classes which immediately follow belong to this division. 



223. The Follicle. — One-celled, simple pistils, like those 



Fig. in. — Group of FoUicles 

 and a Single Follicle of tlie 

 Monkshood. 



