Section XII. MODIFICATIONS OF THE RECEPTACLE.
Fig. 356. Longitudinal section of flower of Silene Pennsylvanica, showing stipe between calyx and corolla.
Fig. 357. Flower of a Cleome of the section Gynandropsis, showing broadened receptacle to bear petals, lengthened stipe below the stamens, and another between these and pistil.
Fig. 358. Pistil of Geranium or Cranesbill.
Fig. 359. The same, ripe, with the five carpels splitting away from the long beak (carpophore), and hanging from its top by their recurving styles.
[323.] The Torus or Receptacle of the flower ([237], Fig. [223]) is the portion which belongs to the stem or axis. In all preceding illustrations it is small and short. But it sometimes lengthens, sometimes thickens or variously enlarges, and takes on various forms. Some of these have received special names, very few of which are in common use. A lengthened portion of the receptacle is called
A Stipe. This name, which means simply a trunk or stalk, is used in botany for various stalks, even for the leaf-stalk in Ferns. It is also applied to the stalk or petiole of a carpel, in the rare cases when there is any, as in Goldthread. Then it is technically distinguished as a Thecaphore. When there is a stalk, or lengthened internode of receptacle, directly under a compound pistil, as in Stanleya and some other Cruciferæ, it is called a Gynophore. When the stalk is developed below the stamens, as in most species of Silene (Fig. [356]), it has been called an Anthophore or Gonophore. In Fig. [357] the torus is dilated above the calyx where it bears the petals, then there is a long internode (gonophore) between it and the stamens; then a shorter one (gynophore) between these and the pistil.
[324.] A Carpophore is a prolongation of receptacle or axis between the carpels and bearing them. Umbelliferous plants and Geranium (Fig. [358, 359]) afford characteristic examples.