42 



ELEMENTS OF BOTANY. 



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

 tration. 



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





Fio. K!.— ;V sIijiuIh rry, t^tunvinp; 

 the H(!LMl8 (iiclicniuj iiuiiiLTtieil iu thu 

 llcsliy rt'coptiiulu. 



„ .--llAx 



''•.Ja ~ "Sail vt ^'I'l 



■"■'■?■■ A" s 

 Fig. 84 — A rusi)bc'rr3'. 



Fig. 85. — A blockbcrry. 



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

 wheat, rye, ami Indian corn. 



A nut 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 cu pule ; the chestnut in a prickly bm\ 



Fig. 86.— Samiira of tho maplo. 



Fio. 87.— Samara of 

 the nilanthns. 



FlQ. 88.— Follicle 

 (if acohito. 



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. 8G), elm, tulip tree, and ailau- 

 thus (Fig. 87). 



