VIOLET FAMILY - Violaceae: Blue and Purple Violets
Lacking perfume only to be a perfectly satisfying flower, the Common Purple, Meadow, or Hooded Blue Violet (V. cucullata) has nevertheless established itself in the hearts of the people from the Arctic to the Gulf as no sweet-scented, showy, hothouse exotic has ever done. Royal in color as in lavish profusion, it blossoms everywhere--in woods, waysides, meadows, and marshes, but always in finer form in cool, shady dells; with longer flowering scapes in meadow bogs; and with longer leaves than wide in swampy woodlands. The heart-shaped, saw-edged leaves, folded toward the centre when newly put forth, and the five-petalled, bluish-purple, golden-hearted blossom are too familiar for more detailed description. From the three-cornered stars of the elastic capsules, the seeds are scattered abroad.
In shale and sandy soil, even in the gravel of hillsides, one finds the narrowly divided, finely cut leaves and the bicolored beardless blossom of the Bird's-foot Violet (V. pedata), pale bluish purple on the lower petals, dark purple on one or two upper ones, and with a heart of gold. The large, velvety, pansy-like blossom and the unusual foliage which rises in rather dense tufts are sufficient to distinguish the plant from its numerous kin. This species produces no cleistogamous or blind flowers. Frequently the Bird's-foot Violet blooms a second time, in autumn, a delightful eccentricity of this family. The spur of its lower petal is long and very slender, and, as might be expected, the longest-tongued bees and butterflies are its most frequent visitors. These receive the pollen on the base of the proboscis.
In course of time the lovely English, March, or Sweet Violet (V. odorata), which has escaped from gardens, and which is now rapidly increasing with the help of seed and runners on the Atlantic and the Pacific coasts, may be established among our wild flowers. No blossom figures so prominently in European literature. In France, it has even entered the political field since Napoleon's day. Yale University has adopted the violet for its own especial flower, although it is the corn-flower, or bachelor's button (Centaurea cyanus) that is the true Yale blue. Sprengel, who made a most elaborate study of the violet, condensed the result of his research into the following questions and answers, which are given here because much that he says applies to our own native species, which have been too little studied in the modern scientific spirit:
"1. Why is the flower situated on a long stalk which is upright, but curved downward at the free end? In order that it may hang down; which, firstly, prevents rain from obtaining access to the nectar; and, secondly, places the stamens in such a position that the pollen falls into the open space between the pistil and the free ends of the stamens. If the flower were upright, the pollen would fall into the space between the base of the stamen and the base of the pistil, and would not come in contact with the bee.
"2. Why does the pollen differ from that of most other insect-fertilized flowers? In most of such flowers the insects themselves remove the pollen from the anthers, and it is therefore important that the pollen should not easily be detached and carried away by the wind. In the present case, on the contrary, it is desirable that it should be looser and drier, so that it may easily fall into the space between the stamens and the pistil. If it remained attached to the anther, it would not be touched by the bee, and the flower would remain unfertilized.
"3. Why is the base of the style so thin? In order that the bee may be more easily able to bend the style.
"4. Why is the base of the style bent? For the same reason. The result of the curvature is that the pistil is much more easily bent than would be the case if the style were straight.
"5. Finally, why does the membranous termination of the upper filament overlap the corresponding portions of the two middle stamens? Because this enables the bee to move the pistil and thereby to set free the pollen more easily than would be the case under the reverse arrangement."