DEHISCENT FRUITS 73 



92. Distinction between Nuts and Achenes. — In very 

 small fruits it is not easy to distinguish between a nut and 

 an achene, nor is it very material. Technically, an achene 

 is a fruit composed of a single carpel, a nut of two or more 

 which have become so completely fused together that their 

 separate parts can be detected only by examining the 

 unripe seed vessel in the flower. Botanists apply the 

 terms very loosely, and the beginner need not be distressed 

 if he can not classify exactly all the specimens he meets 

 with. In general, the larger, harder, and bonier fruits of 

 the kind are called nuts. The family to which a speci- 

 men belongs must also be taken into consideration. For 

 instance, the achene being the characteristic fruit of the 

 sunflower family, any puzzling specimen of that family, 

 like the cockle bur, would naturally be classed as an 

 achene. 



PRACTICAL QUESTIONS 



1 . Name all the indehiscent fruits you can think of that are good 

 for food or other purposes. 



2. Make a list of the commonest indehiscent fruits of your neighbor- 

 hood. 



3. Which of these are useful for any purpose? 



4. Which are troublesome weeds ? 



DEHISCENT FRUITS 



Material. — Simple follicles of larkspur, milkweed, etc. ; a pod of 

 pea or bean ; pods of any species of the mustard family, or of the trum- 

 pet vine (Tecomd) ; cotton, okra, iri.s, or Indian shot (^Canna). Cotton 

 or okra are preferable if they can be obtained, because the parts are 

 large and well defined. 



93. Simple, or Monocarpellary Fruits. — Pod, or capsule, 

 is the general name given to all dehiscent fruits. The 

 latter term is properly confined to pods of more than one 

 carpel, but the distinction is not strictly observed by bot- 

 anists. The simplest possible kind of a pod is 



94. The Follicle, of which the larkspur, milkweed, marsh 

 marigold, etc., are familiar examples. It is composed of 



