STRUCTURAL BOTANY. 79 



/3, DEniSCEHT DET FEUITS 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 which 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, silicjue of Car- 

 damine dehiscent). 



151. A siLicLE or POUCH is avery 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.) 



153. A CAPSULE is the pod of any compoimd 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 septieidal, 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 Hypericum, 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- 

 drbn. Iris, etc. 



Septifragal dehiscence is that modification of either 

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

 dissepiments remain united in the axis, as in Convol- 

 vulus. 



