410 



DICOTYLEDONES. 



as much as a foot in length) on whose upper edge a lid-like structure is found 

 (Fig. 420). In this pitcher, as among the Sarraceniace, a fluid is secreted 

 which is able to digest the animals captured (sometimes rather large) and which 

 corresponds in some degree to the gastric juice. 



Order 5. Violacese (Violets). The flowers are $ , and gener- 

 ally zygomorphic, hypogynous, with S5, P5, A5, Gr3 (Fig. 421). 

 The stamens are closely applied to the ovary, they have a very 

 short filament, and at their summit generally a membranous 

 appendage formed by the prolongation of the connective (Fig. 

 422 g). The ovary is unilocular with 3 parietal placentae; style 



FIG. 421. Diagram of 

 Viola. 



FIG. 422. The large-flowered form of Viola tricolor . A the 

 flower in median longitudinal section ; B the gynceceum. 



undivided (Fig. 422 B). The fruit is usually a 3-valved capsule, 

 opening along the dorsal sutures (Fig. 423). Embryo straight ; 

 endosperm fleshy (Fig. 425). Many are herbaceous plants (e.g. 

 Viola), but in the Tropics shrubs are also found (e.g. Tonidium) ; 

 a few are lianes ; the leaves are scattered, with stipules, and 

 involute in the bud. 



Viola. The sepals are prolonged backwards beyond the point of 

 insertion (appendiculate) ; the corolla is polypetalous, descending 

 imbricate, and zygomorphic, its anterior petal being larger than the 

 others and provided with a spur (Fig. 421). The 2 anterior of the 

 5 almost sessile stamens are provided with a spur-like nectary, 

 which protrudes a considerable distance into the petaloid spur 

 (Figs. 421, 422 n, sp). The style is club-like, and bears the 



