254 DfDEHISCENT AND DEHISCENT FRUITS. 



530. Where the sutures are formed, there are usually two bundles 

 of fibro-vascular tissue (fig. 443), one on each edge. The edges of the 

 sutures are often so ultimately united, as not to give way when the fruit 

 is ripe. In this case it is called indehiscent (in, used in the sense 



of not, and dehisco, I open), as in the Acorn and Nut; at 

 other times the fruit opens between the two vascular bundles, 

 either at the ventral or dorsal suture, so as to allow the 

 seeds to escape, and then it is dehiscent (dehisco, I open). 

 By this dehiscence the pericarp becomes divided into dif- 

 ferent pieces, which are denominated valves, the fruit being 

 univalvular, Uvalvular, or multivalvular, &c., according as 

 there are one, two, or many valves. These valves separate 

 either completely or partially. In the latter case, the divi- 

 sions may open in the form of teeth at the apex of the fruit, 

 the dehiscence being apicular, as in Caryophyllacece (fig. 

 444 v), or as partial slits of the ventral suture, when the 

 carpels are only free at the apex, as in Saxifrages. 



531. indchiscent Fruits are either dry, as the Nut, or fleshy, as the 

 Cherry and Apple. They may be formed by one or several carpels ; 

 and in the former case they usually contain only a single seed, which 

 may become so incorporated with the pericarp as to appear to be naked. 

 Such fruits are called pseudo-spermous (\^iv^f, false, and aTri^x, seed), 

 or false-seeded, and are well seen in the gram of Wheat. In such 

 cases the presence of the style or stigma determines their true nature. 



532. i>< iii. ni Fruits, when composed of single carpels, may open 

 by the ventral suture only, as in the follicles of Pseony; by the dorsal 

 suture only; or by both together, as in the legume of the Pea and 

 Bean; in which cases the dehiscence is called sutural. When composed 

 of several united carpels, the valves may separate through the dissepi- 

 ments, so that the fruit will be resolved into its original carpels, as in 

 Rhododendron, Colchicum, &c. This dehiscence, in consequence of 

 taking place through the lamella of the septum, is called septicidal 

 (septum and ccedo, I cut) (figs. 445, 446). The valves may separate 

 from their commissure, or central line of union, carrying the placentas 

 with them, or they may leave the latter in the centre, so as to form 

 with the axis a column of a cylindrical, conical, or prismatic shape, 

 which has received the designation of columella (fig. 447 c). The 

 union between the edges of the carpels may be persistent, and they 

 may dehisce by the dorsal suture, or through the back of the locula- 

 ments, as in the Lily and Iris (fig. 448). In this case the valves are 

 formed by the halves of the cells, and the septa either remain united 

 to the axis, or they separate from it, carrying the placentas with them 



Fig. 444. Capsule or dry seed-vessel of Cerastium viscosum after dehiscence. c, Persistent 

 calyx, p, Pericarp dividing at the apex, r, into ten teeth, which indicate the summits of as 

 many valves united below. 



