Wild Flower Families
Indian Pipe Family
Read More Articles About: Wildflower Families
( Originally Published 1908 )
ALTHOUGH the Purslane family is a comparatively large group it contains but two species of wild flowers which are widely distributed in the United States. The characters of the family are fairly well illustrated by the familiar Pussley, one of the worst of our garden weeds, and the almost equally familiar Portulacca of our flower-beds. The latter is indeed very closely related to the former, and in some localities it has escaped from gardens to become a wild flower. Most of the members of this family have more or less thickened leaves and stems and the flowers are commonly composed of two sepals, four or five petals, an equal number of stamens and one pistil.
SPRING BEAUTIES. Two species of Spring Beauty or Claytonia commonly occur in the United States. The Virginia Spring Beauty has a wider distribution than the Carolina Spring Beauty and is the species most commonly found in the middle and western states. In New England and the eastern region generally the Carolina form is the one usually present. The two species resemble each other, differing chiefly in the shape of the leaves: in the Virginian form these are four or five inches long, and linear-lanceolate in shape; in the Carolinian form they are two or three inches long, and ovate-lanceolate in shape. The blossoms are very similar.
The Spring Beauty is an excellent example of what the botanists call protandry,—that is, the shedding of the pollen by the stamens before the the stigma opens. The first day that the petals unfold the stamens stand erect around the pistil, and are already shedding their pollen. But the three-lobed stigma of the pistil is not exposed; the stigmatic surfaces are tightly pressed against each other. On this first day the bees visit the blossom to plunder it of pollen and nectar, but on account of the closed stigmas they cannot fertilize the ovaries of the pistil, either with the pollen of the same or that from another flower. On the second day the filaments have bent outward in such a way as to press the anthers against the petals, and thus to keep them away from the stigmas which have now opened. If at this time the flower is visited by a bee more or less covered with pollen from another plant, some of the pollen-grains will pretty surely be brushed upon the stigmatic surface, and in consequence cross-fertilization will result. The statement has frequently been made that the closing of the petals must bring about self-fertilization, but this in general is not the case. Mr. Charles Robertson, who has studied with his usual care the pollination of the Virginia Spring Beauty, has said:
If self-fertilization by closing of the flower occurs, it is after the anthers have been exposed to insects for two days and the stigma for one, but many flowers which I marked exposed their stigmas again on the third day, showing that fertilization of any kind had failed on the day before." My own observations on the Carolina Spring Beauty indicate a similar behavior of the flowers of this species.
The blossoms of the Spring Beauty are visited by an extraordinary number and variety of insects: in the case of the Virginia Spring Beauty Mr. Robertson has recorded seventy-one species of such visitors. The workers of the common honey bee are among the most abundant of these, frequenting the flowers in quest of both nectar and pollen. Various species of queen bumble-bees are also to be found, as well as numerous kinds of smaller bees. Thirty-one species of two-winged flies were seen, most of them making use of both nectar and pollen, while nine sorts of butterflies came to suck the nectar. Even the little Spotted Ladybeetle came to feed upon the pollen.
Like so many other plants the Spring Beauties sometimes exhibit decided variations in the parts of the flower. In Michigan pure white flowers smaller than usual have been found, with short filaments and abortive anthers.