The Elements of Botany, For Beginners and For SchoolsGray, Asa
Science
The Elements of Botany, For Beginners and For Schools
Gray, Asa
Plants
_Anatropous_ or _Inverted_, as in Fig. 347, the commonest kind, so
called because in its growth it has as it were turned over upon its
stalk, to which it has continued adnate. The organic base, or chalaza,
thus becomes the apparent summit, and the orifice is at the base, by
the side of the hilum or place of attachment. The adnate portion of the
funiculus, which appears as a ridge or cord extending from the hilum to
the chalaza, and which distinguishes this kind of ovule, is called the
RHAPHE. The amphitropous ovule (Fig. 346) has a short or incomplete
rhaphe.
322. Fig. 348-352 show the stages through which an ovule becomes
anatropous in the course of its growth. The annexed two figures are
sections of such an ovule at maturity; and Fig. 355 is Fig. 353
enlarged, with the parts lettered.
Section XII. MODIFICATIONS OF THE RECEPTACLE.
[Illustration: Fig. 356. Longitudinal section of flower of Silene
Pennsylvanica, showing stipe between calyx and corolla.]
[Illustration: 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.]
[Illustration: Fig. 358. Pistil of Geranium or Cranesbill.]
[Illustration: 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.
[Illustration: Fig. 360. Longitudinal section of a young strawberry,
enlarged.]
[Illustration: Fig. 361. Similar section of a young Rose-hip.]
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