STRUCTURAL BOTANY. 79 



ft DEHISCENT DRY FRUITS FROM A COMPOUND PISTIL. 



150, The siLiQUE is a slender, usually linear, 2-carpel- 

 led, 2-valved, 2-celled capsule, with two parietal placentae, 

 between w^hich a thin partition is drawn, from which, at 

 maturity, the valves separate. The partition is a false 

 one, an expansion of the placentae (Fig. 7, silique of Car- 

 damine dehiscent). 



151. A siLicLE or POUCH is a very short silique, nearly as 

 wide as long, or not over four times as long as wide. It 

 belongs to the siliculous Crucifers. (Its valves are inde- 

 hiscent in Senebiera.) 



159. A CAPSULE is the pod of any compound pistil, 

 whether regularly dehiscent, or opening by pores, or 

 bursting irregularly. But usually it splits open length- 

 wise into equal pieces or valves. 



The regular dehiscence of a capsule takes place in one 

 of three ways. We distinguish a septicidal, loculicidal, 

 and septifragal dehiscence. 



Septicidal dehiscence is that mode of dehiscence in 

 which a capsule splits through the partitions, dividing 

 each of them into halves (as in Hypeiicum, Fig. 8, lower 

 part of the capsule, the upper being cut away). 



Loculicidal dehiscence is a splitting open through the 

 middle of the back of each cell of the pod (Fig. 9, lower 

 half of the capsule), as in Cassandra, Cassiope, Oxyden- 

 dron. Iris, etc. 



Septifragal dehiscence is that modification of either 

 the foregoing two, in wliicb the valves fall off, while the 

 dissepiments remain united in the axis, as in Convol- 

 vulus. 



