62 



STKUCTURAL BOTANY. 



[51, 52. 



the seed while maturing. In Mignonette (165), how- 

 ever, it opens, exposing the seed, immediately after 

 flowering. The membranous pericarp of Cohosh (Cau- 

 lophyllum) falls away early, leaving the seed to ripen 

 naked. In Yew (Taxus) the seed is never inclosed 

 wholly by its fleshy pericarp ; but in most of the other 

 Coniferse, the close-pressed, carpellary scales cover the 

 seeds. One-seeded fruits, like those of Buttercups, etc., 

 are liable to be mistaken for naked seeds. 



172 



Capsule, 167, of Scrophulavia, 2-celled; 168,. of Datura Stramonium; 169, of Iris; 170, showing its mode 

 of dehiscence (loculicidal). 171, of Colchicum, 3-celled. 172, Regma, ripe fruit of Geranium, the carpels 

 (cocci) separating from the axis and bending upward on the elastic styles. 



148. Dehiscence. The fleshy pericarp is always 

 indehiscent. Its seeds are liberated only by its decay, 

 or bursting in germination. So also in many cases 

 the dry pericarp, as the acorn. But more commonly 

 the dry fruit, when arrived at maturity, opens in some 

 way, discharging its seeds. Such fruits are dehiscent. 

 Dehiscence is either valvular, porous, or circumscissile ; 

 valvular, when the pericarp opens vertically along the 

 sutures, forming regular parts called valves. These 

 valves may separate quite to the base, or only at the 

 top, forming teeth, as in Chickweed. "We notice four 

 modes of valvular dehiscence, viz. : 



