There are three families, all represented within the United States. The first (_Nelumbieæ_) has but a single species, the yellow lotus or nelumbo (_Nelumbo lutea_), common in the waters of the west and southwest, but rare eastward (Fig. 101, _F_). In this flower, the end of the flower axis is much enlarged, looking like the rose of a watering-pot, and has the large, separate carpels embedded in its upper surface. When ripe, each forms a nut-like fruit which is edible. There are but two species of _Nelumbo_ known, the second one (_N. speciosa_) being a native of southeastern Asia, and probably found in ancient times in Egypt, as it is represented frequently in the pictures and carvings of the ancient Egyptians. It differs mainly from our species in the color of its flowers which are red instead of yellow. It has recently been introduced into New Jersey where it has become well established in several localities. The second family (_Cabombeæ_) is also represented at the north by but one species, the water shield (_Brasenia_), not uncommon in marshes. Its flowers are quite small, of a dull-purple color, and the leaves oval in outline and centrally peltate, _i.e._ the leaf stalk inserted in the centre. The whole plant is covered with a transparent gelatinous coat. The third family (_Nymphæaceæ_) includes the common white water-lilies (_Castalia_) and the yellow water-lilies (_Nymphæa_) (Fig. 102, _A_). In the latter the petals are small and inconspicuous (Fig. 102, _C_, _p_), but the sepals are large and showy. In this family the carpels, instead of being separate, are united into a large compound pistil. The water-lilies reach their greatest perfection in the tropics, where they attain an enormous size, the white, blue, or red flowers of some species being thirty centimetres or more in diameter, and the leaves of the great _Victoria regia_ of the Amazon reaching two metres or more in width. The third order of the _Aphanocyclæ_ (_Rhœadinæ_ or _Crucifloræ_) comprises a number of common plants, principally characterized by having the parts of the flowers in twos or fours, so that they are more or less distinctly cross-shaped, whence the name _Crucifloræ_. There are four families, of which the first is the poppy family (_Papaveraceæ_), including the poppies, eschscholtzias, Mexican or prickly poppy (_Argemone_), etc., of the gardens, and the blood-root (_Sanguinaria_), celandine poppy (_Stylophorum_), and a few other wild plants (see Fig. 103, _A-I_). Most of the family have a colored juice (latex), which is white in the poppy, yellow in celandine and _Argemone_, and orange-red in the blood-root. From the latex of the opium poppy the opium of commerce is extracted.