FRUITS 



261 



seeds or kernels do you find in the dehiscent pod? How 

 many in the indehiscent one? Would it be of any advan- 

 tage for a one-seeded pod to open? Remove the kernel 

 from the indehiscent fruit ; has it any covering besides the 

 shell ? Which is the pericarp, and which the seed coat ? 



295. The nut is easily recognized by its hard, bony cover- 

 ing, containing usually, when mature, a single large seed that 

 fills the interior. Care should be taken not to confound with 

 true nuts, large bony seeds, like those of the buckeye, horse- 



376 377 



Figs. 376, 377. — Nut of the pecan 

 tree : 376, exterior ; 377, cross section. 



Figs. 378, 379. — Nutlike seeds: 

 378, horse-chestnut ; 379, seed of the 

 fetid sterculia. 



chestnut, date, and the Brazil nut sold in the markets. In 

 the true nut, the hard covering is the seed vessel, or pericarp, 

 and not a part of the seed itself, though it often adheres to it 

 so closely as to seem so. In bony seeds, like those of the horse- 

 chestnut and persimmon, the hard covering is the outer seed 

 coat. The distinction is not always easy to make out unless 

 the seed can be examined while still attached to the placenta 

 of the fruit. 



296. The akene, of which we have 

 examples in the tailed fruit of the 

 clematis, the tiny pits on the straw- 

 berry, and the so-called seeds of the 

 thistle, dandelion, and sunflower, is a 

 small, dry, one-seeded, indehiscent 

 fruit, so like a naked seed that it is 

 generally taken for one by persons not 

 acquainted with botany. It is the 



380 



3S1 



Figs. 380, 381. — Akcnes 

 (magnified) : 3S0, of buck- 

 wheat ; 381, of cinquefoil. 



