This order, which many botanists combine with the preceding one, also consists of only two genera; viz., _Cabomba_ and _Hydropeltis_; and of these _Cabomba aquatica_ is a stove aquatic, and _Hydropeltis purpurea_ is a hardy water plant, with peltate leaves, and dull purple flowers. ORDER IX. NYMPHÆACEÆ.—THE WATER-LILY TRIBE. [Illustration: FIG. 110.—THE FLOWER, LEAF, AND SEED-VESSEL OF THE WHITE WATER-LILY, GREATLY REDUCED IN SIZE.] The principal genera in this order are Nymphæa, Euryale, Victoria, Nuphar, and Nelumbium. The flowers of the common White Water-lily (_Nymphæa alba_) consist of numerous sepals, petals, and stamens, all of which might be mistaken for petals, being principally distinguished by their colour. The sepals, (_a_ in _fig_. 110,) are green on the outside, but they are white within, and of the same fleshy substance as the petals (_b_). The stamens (_c_) look like narrow yellow petals; they are pointed, and bear the pollen in two lobes near the point, which open longitudinally when ripe. The inner row of stamens are without anthers, and form a kind of vandyke edging to the pistil, as shown at _e_. The pistil consists generally of sixteen carpels, growing together into a vase-like, many-celled berry, as shown at _d_; the spreading stigmas, which have also grown together, forming a kind of lid. The carpels are completely enclosed by the receptacle which rises up round them, and forms a thick fleshy covering, as shown at _f_. The seeds are numerous, and they are covered with a thick leathery skin. The embryo is small, and it is surrounded by a great mass of floury albumen. The leaves (_g_) are large and nearly round; and the main root, which is called a rhizoma, is thick and fleshy, and is, indeed, an underground stem. There are several kinds of Nymphæa, the most remarkable of which is the Egyptian Lotos (_N. Lotos_), the flowers of which are white tinged with pink; and both the roots and seeds of which are eaten. _Euryale_ is a genus of South American Water-lilies, generally with small flowers, and large rough leaves; and _Victoria regina_, also a native of South America, is perhaps the most magnificent Water-lily in the world; the leaf, which is peltate and turned up at the brim, being of a deep crimson on its lower surface, is upwards of six feet in diameter; and the flowers are more than a foot in diameter, with a corolla of more than a hundred large white petals tinged with pink.