Part 103. The Reproductive System - The Crowfoot Family. Part 2

The ovules of marsh-marigolds are essentially like those of flax and of all the crowfoot family. We may distinguish in each ovule a little stalk, the funicle,²⁰ which continues as a ridge, the raphe,²¹ along the side of the main part or body of the ovule. At the small end is a minute opening, the micropyle.²² An ovule which is bent so that the micropyle comes next to the funicle, or point of attachment, is termed anat-ropous.²³

²⁰ Fu'-ni-cle - L. funiculus, diminutive of funis, a cord.

²¹ lla'phe - Gr. rhaphe, a seam.

²² Mi-cro-pyle - Gr. micros, small; pyle, gate.

²³ A-nat'-ro-pous - Gr. ana, back; trepein, turn.

Gynoecia essentially like those of marsh-marigold are found in Christmas roses, columbines, peonies, and monkshoods (Figs. 178, 282, 287, 284). In anemonies (Fig. 297), each carpel contains at first the rudiments of several ovules, but only one (the lowest) develops, the rest remaining mere rudiments. Many genera, as for example, crowfoots, mouse-tails, meadow rues, and clematises (Figs. 285, 290, 293) have only a single ovule in each carpel from the first. In a few cases it happens, as in fennel-flowers (Fig. 286) and certain species nearly related to the Christmas rose, that the carpels are more or less united with one-another at the base, thus forming a compound pistil comparable to that of flax. As a result of this union of the carpels there is formed a single compound placenta which being at the center of the ovary is termed axile. It is obvious that a compound pistil, say of five carpels, requires less material than an equal number of separate carpels of the same size, just as it takes less bricks to build a chimney with five flues than it does to make for each flue a separate chimney. Almost all of the crowfoot family have simple pistils, i. e., consisting of but one carpel. The number of simple pistils may be many, as in crowfoots, mouse-tails, and anemonies; several or few, as in Christmas rose, columbines, peonies, and monkshoods; or only one, as in bane-berries.

When both stamens and pistils are present (as in nearly all of the crowfoot family) the flower is said to be perfect; it is imperfect when either set of essential organs is absent or rudimentary. Flowers having stamens alone are called staminate; those with pistils alone, pistillate. In certain species of clematis both perfect and imperfect flowers occur; such plants are termed polygamous.²⁴

²⁴ Perfect flowers are symbolized in botany by the sign 9 , staminate by ♂, and pistillate by ♀. The expression g ♂ ♀ would thus stand for polygamous.

Andrcecia consisting of an indefinite number of stamens like those of marsh-marigold occur in the wood-anemony, peonies, and certain species of clematis (Figs. 194, 282, 291). Among cultivated peonies we often find flowers which have become "double" as the gardeners say. In these the outer stamens are replaced by more or less petal-like leaf-members which, however, differ considerably in shape from the petals, and show clearly their closer homology with filaments by numerous intermediate forms (Figs. 294, 295). What here takes place as an abnormality throws light upon the homology of certain curious and puzzling organs often called "nectar-leaves" which take the place of the outer stamens in many flowers of the crowfoot family. In some anemonies-as in the wood-anemony-the outer stamens have anthers, while in other species like the pasque-flower the outer filaments are destitute of anthers but instead have swollen tips which secrete nectar (Figs. 194, 296 A). Antherless stamens are called staminodes.²⁵ The nectar-leaves are most probably of this nature. The Christmas rose has tubular staminodes; the mouse-tail, staminodes somewhat club-shaped and bent; crowfoots have them broadly expanded and petal-like; fennel-flowers, more or less petal-like with a peculiar pouch; while in columbines there is an outer set of colored staminodes forming trumpet-like spurs which secrete nectar copiously, and next to the carpels two inner sets of five each which produce no nectar and are very thin and colorless (Figs. 284D, 285II, 296B-E). It is not unusual for botanists to speak of the petal-like nectar-leaves of this family as petals, but this is not in accord with the modern view of their homology.

²⁵ Stam'-in-ode - L. stamen, staminis, stamen; Gr. eidos, a form.

Most of the crowfoot family are like marsh-marigolds in having no corolla. In peonies are found unmistakable petals. These show that they belong to the perianth, not only by having a much wider base than the stamens, but also by the occurrence of transitional forms connecting them with sepals, as illustrated in Fig. 294. The series as there shown connects also sepals, bractlets, and bracts. Anemonies and fennel-flowers, as we have seen, have involucres or involucels which are sometimes so close to the flower as to be easily mistaken for calyx, and which indeed differ from calyces only in being separated from the floral whorls by a more or less developed internode. The case is especially deceptive when the sepals are petaloid, i. e., brightly colored like petals, and the involucre is close to the flower. Flowers without a corolla are said to be apetalous.²⁶ When as in peonies the flowers have calyx, corolla, stamens, and pistils, they are described as complete.

²⁶ A-pet'al-ous - Gr. a, without, petalon, petal.