402 



AMPELIDR&:, OR GRAPE TRIBE. 



567. The next order to be noticed is that of AMPELIDE^E, 

 which is principally important as containing the common Grape 

 Vine, which will serve as an illustration of its characteristic 

 structure. Nearly all the plants of the group are climbers, and 

 most of them support themselves by tendrils. The nature of 

 these organs differs, in almost every tribe of plants which pos- 

 sesses them. If the Pea be examined, its tendrils will be seen 

 to consist in a prolongation of the midrib or central stalk, from 

 each side of which the leaflets arise. In some plants, this office 

 is performed by the prolonged tips of the petals, which twine 

 round any object in their neighbourhood that can afford them 

 support. In the Vine, the tendrils are developed from a num- 

 ber of supernumerary barren flower-stalks. The flowers of the 

 Vine grow on short stalks, which diverge from others, and these 

 branch from the central stem ; in this manner, when the fruit 

 is ripe, a cluster is formed, differing considerably from that, in 

 which the fruit-stalks at once proceed from the stem, as they do 

 in the Currant. The former arrangement is called a panicle, the 

 latter a raceme. The calyx is very small and almost undivided, 



... 



Fio. 150. PORTIONS OF THE FLOWER OF COMMON VIWE. A, flower opening ; a, calyx , 

 fc, corolla, the petals detached at the bottom but united at the top; c, stamens; d, 

 glands. B, ovarium surrounded by the stamens. C, vertical section of ovarium, show- 

 ing its two cells and ascending ovules ; a, calyx ; b, origin of petals ; c, glands ; d, stigma. 

 D, horizontal section. E, section of ripe fruit. 



looking like an expansion of the disk ; within it are seen, in the 

 bud, five petals which hold together at the point, though sepa- 



