42 



ELEMENTS OF BOTANY. 



distribution by the wind. That of the dandelion will serve as an illus- 

 tration. 



The utricle is an achenium with a loose, bladdery pericarp. 



Fig. 83. — A strawberry, showing 

 the seeds (achenia) immersed in the 

 fleshy receptacle. 



Fig. 84— A raspberry. 



Fig. 85. — A blackberry. 



The caryopsis has the pericarp incorporated with the seed, as in 

 wheat, rye, and Indian corn. 



A n ut is a dry indehiscent fruit with a hard woody or bony shell, as 

 in the acorn, chestnut, and cocoanut. The acorn rests in a cup-shaped in- 

 volucre, termed the cup, or cupule; the chestnut in a prickly bur. 



Fig. 86. — Samara of the maple. 



Fig. 87.— Samara of 

 the ailanthus. 



Fig. 88.— Follicle 

 of aconite. 



A samara? or key-fruit, is either a nut or an achenium, or any other 

 dry fruit furnished with a wing to favor its distribution by the wind. Of 

 this kind are the fruits of the maple (Fig. 86), elm, tulip tree, and ailan- 

 thus (Fig. 87). 



