Among the commoner members of the order are the mignonettes (_Resedaceæ_) and the violets (_Violaceæ_), of which the various wild and cultivated species are familiar plants (Fig. 104, _A_, _M_). The sundews (_Droseraceæ_) are most extraordinary plants, growing in boggy land over pretty much the whole world. They are represented in the United States by several species of sundew (_Drosera_), and the still more curious Venus's-flytrap (_Dionæa_) of North Carolina. The leaves of the latter are sensitive, and composed of two parts which snap together like a steel trap. If an insect lights upon the leaf, and touches certain hairs upon its upper surface, the two parts snap together, holding the insect tightly. A digestive fluid is secreted by glands upon the inner surface of the leaf, and in a short time the captured insect is actually digested and absorbed by the leaves. The same process takes place in the sundew (Fig. 104, _N_) where, however, the mechanism is somewhat different. Here the tentacles, with which the leaf is studded, secrete a sticky fluid which holds any small insect that may light upon it. The tentacles now slowly bend inward and finally the edges of the leaf as well, until the captured insect is firmly held, when a digestive process, similar to that in _Dionœa_, takes place. This curious habit is probably to be explained from the position where the plant grows, the roots being in water where there does not seem to be a sufficient supply of nitrogenous matter for the wants of the plant, which supplements the supply from the bodies of the captured insects. [Illustration: FIG. 105.--Types of _Aphanocyclæ_ (_Cistifloræ_). _A_, _B_, leaves of the pitcher-plant, _Sarracenia_ (_Sarraceniaceæ_). _A_, from the side; _B_, from in front, × ½. _C_, St. John's-wort (_Hypericum_), × ½. _D_, a flower, × 1. _E_, the pistil, × 2. _G_, cross-section of the ovary, × 4. _H_, diagram of the flower.]