VIOLACE^E, OR VIOLET TRIBE. 375 



mostly composed of still humbler plants, but containing some 

 well-known species of general interest. This is the order VIOLACE^E, 

 or Violet tribe, the largest of the British species of which is the 

 common Pansy or Heartsease ; this will be convenient, there- 

 fore, to describe in illustration. On looking at the leaves, they 

 will be found to be rather small, and to arise by long stalks, at 

 the base of which are a pair of large stipules ; these are very 

 characteristic of the order. The flower consists of five narrow 

 sepals, some much larger than the rest ; which are usually pro- 

 longed in a curious manner at the base. The corolla consists of 

 five petals, of which, in the Pansy and most other species, two 

 stand nearly erect, so as to appear above the others. These two 

 in the Pansy are differently-coloured ; and a third, standing in 

 front of them, has a short horn or spur at its base. The stamens 

 are also five in number, and generally of irregular form, possess- 

 ing no proper filament, but having a membranous expansion in 

 place of it, which is elongated above the anthers ; two of thew, 

 in the Pansy, have long projections, which are hidden in the 

 horn of the petal. The anthers are often coherent to each 

 other, and lie close upon the ovary. The ovarium is superior, 

 and contains but one cell ; it possesses, however, three parietal 

 placentae (Fig. 84, . 434), to which many ovules are usually 

 attached. There is but a single style ; and the stigma is covered 

 with a kind of hood, so that access can only be gained to it by 

 an aperture on one side. For this singular conformation, no 

 use has been assigned. When the fruit is ripe, it is still sur- 



O * * 



rounded by the calyx ; it is an oblong shining case, which splits 

 into three valves, having the seeds adherent to the middle of 

 each. The Heartsease of the gardens has been greatly im- 

 proved in its beauty as a flower by cultivation ; and a number 

 of varieties, differing chiefly in their colours, are known to florists. 

 The common Sweet Violet has no rival among flowers, if we 

 seek for delicate fragrance ; and this is not improved by culti- 

 vation. 



539. This order is readily known from all other hypogynous 

 Exogens, by its persistent calyx, its irregular flowers, and by the 

 three narrow parietal placentae situated in the middle of the 



