ITS KINDS. 



317 



617. Scptifragal Dehiscence is a modificalion of either the loculicidal 

 or the septicidal, in wliich the valves fall away, leaving the dissepi- 

 ments behind attaclied to the 



Fig. 586 is a diagram 



axis. 



representing this in a case 

 of loculicidal opening. Fig. 

 587, from the common Morn- 

 ing-Glory, is this modifica- 

 tion of the septicidal mode. 



618. Instead of splitting 

 into separate pieces, the sutures of the pericarp sometimes open for 

 a short distance at their apex only, as in Cerastium and some other 

 Chickweeds, in Tobacco (Fig. 1050), and in the Primrose (Fig. 

 943) ; or by mere pores, as in the Poppy. The pod of the Snap- 

 di'agon opens by the bursting of a hole towards the top of each cell, 

 not corresponding, perhaps, with any suture. Another anomalous 

 mode of dehiscence, namely, the circumcissile, characterizes 



619. The Pyxis or Pjlidium, a pod which opens by a circular hor- 



izontal line cutting off the upper part as a lid. The 

 fruits of the Plantain, Henbane, Amaranth (Fig. 

 575, which is otherwise a utricle), Pimpernel, and 

 Purslane (Fig. 588) are of this kind. 



620. A Silique is a slender two-valved capsule, with 

 two parietal placentfe, from which the 

 valves separate in dehiscence ; as in 

 plants of the Cruciferous or Mustard 

 family (Fig. 589), to the fruit of which the term prop- 

 erly belongs. Usually a false partition is stretched 

 across between the two placenta?, rendering the pod 

 two-celled in an anomalous manner. 



621. A Silicic or Pouch is merely a short silique, its 

 length not moi-e than twice its breadth ; as that of Shep- 

 herd's-Purse, Candytuft, &c. 



622. Aggregate Fruits are those in which a cluster of 

 carpels, all belonging to one flower, are crowded on the 

 receptacle into one mass, as in the raspberry and blackberry taken 

 as a whole (Fig. 564), where the constituent fruits, or ripened carpels, 



5S9 



FIG. 586. Septifragal modification of loculicidal, and, 587, of septicidal, dehiscence. 

 FIG. 588. Pyxis or pod of Purslane, the top separating as a lid. 

 FIG. 589. Silique of Cardamine, iu dehiscence. 



27* 



