FRUIT OR MATURE PISTIL. 



253 



nal succulent covering, zc, formed by modified bracts, which here occupy 

 the place of a pericarp, and display the seed, <?, which is naked, because 

 not contained in a true ovary with a style and stigma. 



441, 1 



441, 2 



528. The part of the pericarp attached to the peduncle is called its 

 base, and the part where the style or stigma existed is the apex. This 

 latter is not always the mathematical apex. In AlchemiUa, Labiata?, 

 and Boraginaceas, it is at the base or side (figs. 400, 401, 402). The 

 style sometimes remains in a hardened form, rendering the fruit apicu- 

 late; at other times it falls off, leaving only traces of its existence. The 

 presence of the style or stigma serves to distinguish certain single- 

 seeded pericarps from seeds. 



529. As in the case of the carpel, so in the mature ovary formed 

 of it, the edges unite towards the axis, and constitute the ventral 

 suture (fig. 443 s v), while the back, corresponding 



with the midrib, is the dorsal suture (fig. 443 s d). The 

 inner suture, in some fruits formed of a single carpel, as 

 the Apricot and Bladder senna, is marked by a distinct 

 furrow or depression, consequent on the folding in- 

 wards of the carpellary edges; and occasionally the 

 outer or dorsal suture is also thus rendered distinctly 

 visible. When the fruit consists of several mature 

 carpels, all meeting in the centre, and united together, 

 then the dorsal suture is also visible externally; but 

 in cases where the placentation is parietal or free cen- 

 tral, then the edges of the separate carpels, being near the surface, may 

 present also externally the marks of the ventral sutures. 



Fig. 441. Fruit of Mirabilis Jalapa. 1. Entire. 2. Cut longitudinally, to show its composi- 

 tion, c c, Lower part of calyx hardened, and forming an outer envelope. /, The true fruit, 

 covered by the calyx. The integuments of the fruit are incorporated with those of the seed, 

 which has been also cut. The fruit is distinguished by the remains of the style, s, at the api- 

 culus or summit 



Fig. 442. Fruit of Taxus baccata, the Yew. 6, Imbricated bracts at its base, i c, Fleshy 

 envelope taking the place of the pericarp. This envelope covers the seed, g, partially, leaving 

 its apex naked. 



Fig. 443. A single carpel of Helleborns foetidus after dehiscence. s rf, Dorsal suture. v, 

 Ventral suture. The carpel, when mature, opens on the ventral suture, and forms the fruit 

 denominated a follicle. 



