Nature and development of plants . 311, C, D) andthe flower is strictly epigynous. In the rose family, which isvery closely connected with the preceding group, this story ofchange in the evolution of the flower is repeated. In the simplerforms the receptacle adheres to the calyx, forming a cup-like28 4i8 THE ROSALES structure that may be rather broad and shallow as in the straw-berry, cinquefoil and blackberry (Fig. 312), but in higher typesthe receptacle more or less completely surrounds the pistils asin the spiraea, avens, rose, agrimony (Fig. 313). In the applefamily, including the apple, p
Nature and development of plants . 311, C, D) andthe flower is strictly epigynous. In the rose family, which isvery closely connected with the preceding group, this story ofchange in the evolution of the flower is repeated. In the simplerforms the receptacle adheres to the calyx, forming a cup-like28 4i8 THE ROSALES structure that may be rather broad and shallow as in the straw-berry, cinquefoil and blackberry (Fig. 312), but in higher typesthe receptacle more or less completely surrounds the pistils asin the spiraea, avens, rose, agrimony (Fig. 313). In the applefamily, including the apple, peach, quince, shadbush, thornapple,hawthorn, the ovules are completely enveloped by the receptacle(Fig. 314, A-C) as in the currants, while in the plum family,with its plum, prune, cherry, peach, almond, apricot members,the pistils are reduced to one and do not adhere to the cup-likereceptacle (Fig. 314, D-F). The senna family has essentially the same type of flower asthe plum save that the pistil usually contains many seeds (nor-. Fig. 314. Flowers and fruits of the apple and plum families: ./, inflor-escence of the apple (Mains). B, section of flower, showing adhesion ofreceptacle to the ovary, epigynous flower. C, sections of the fruit—c, ear-pels of the pistil; r, fleshy receptacle. D, flower of cherry (Primus). E,section of flower—r, cup-like receptacle which falls off as fruit , fruit in section, showing the outer part of the wall of the ovary as afleshy rind and the inner part forming the stone or pit which enclosed asingle seed. mally but one develops in the plum) and splits at maturity intotwo valves, a form of fruit called a pod. For example, in the DEVELOPMENT OF PLANTS 419 honey locust (Gleditsia) and the Kentucky coffee bean (Gymno-cladus), the receptacle forms a shallow cup which bears theregular sepals, petals and usually ten stamens about a singlepistil (Fig. 315, A). The flowers are really monoecious, but inother respects are very suggestive of the
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