Fig. 114.—Calycifloræ (Rosifloræ). A, inflorescence of strawberry (Fragaria), × ½. B, a single flower, × 1. C, section of B. D, floral diagram. E, vertical section of a cherry-flower (Prunus), × 1. F, vertical section of the flower of Spiræa, × 2. G, vertical section of the bud of a wild rose (Rosa), × 1. H, vertical section of the young fruit, × 1. I, section of the flower of an apple (Pyrus), × 1. J, floral diagram of apple.
From the examples given, it will be seen that the order includes not only some of the most ornamental, cultivated plants, but the majority of our best fruits. In addition to those already given, may be mentioned the raspberry, blackberry, quince, plum, and apricot.
Fig. 115.—Calycifloræ (Leguminosæ). A, flowers and leaf of the common pea, Pisum (Papilionaceæ), × ½. t, tendril. st. stipules. B, the petals, separated and displayed, × 1. C, flower, with the calyx and corolla removed, × 1. D, a fruit divided lengthwise, × ½. E, the embryo, with one of the cotyledons removed, × 2. F, diagram of the flower. G, flower of red-bud, Cercis (Cæsalpinaceæ), × 2. H, the same, with calyx and corolla removed. I, inflorescence of the sensitive-brier, Schrankia (Mimosaceæ), × 1. J, a single flower, × 2.
The last order of the Calycifloræ and the highest of the Choripetalæ is the order Leguminosæ, of which the bean, pea, clover, and many other common plants are examples. In most of our common forms the flowers are peculiar in shape, one of the petals being larger than the others, and covering them in the bud. This petal is known as the standard. The two lateral petals are known as the wings, and the two lower and inner are generally grown together forming what is called the “keel” ([Fig. 115], A, B). The stamens, ten in number, are sometimes all grown together into a tube, but generally the upper one is free from the others ([Fig. 115], C). There is but one carpel which forms a pod with two valves when ripe ([Fig. 115], D). The seeds are large, and the embryo fills the seed completely. From the peculiar form of the flower, they are known as Papilionaceæ (papilio, a butterfly). Many of the Papilionaceæ are climbers, either having twining stems, as in the common beans, or else with part of the leaf changed into a tendril as in the pea ([Fig. 115], A), vetch, etc. The leaves are usually compound.
Of the second family (Cæsalpineæ), mainly tropical, the honey locust (Gleditschia) and red-bud (Cercis) ([Fig. 115], G) are the commonest examples. The flowers differ mainly from the Papilionaceæ in being less perfectly papilionaceous, and the stamens are almost entirely distinct ([Fig. 115], H). The last family (Mimosaceæ) is also mainly tropical. The acacias, sensitive-plant (Mimosa), and the sensitive-brier of the southern United States (Schrankia) ([Fig. 115], I) represent this family. The flowers are quite different from the others of the order, being tubular and the petals united, thus resembling the flowers of the Sympetalæ. The leaves of Mimosa and Schrankia are extraordinarily sensitive, folding up if irritated.