(Oxalis violacea) Wood-sorrel family Flowers - Pinkish purple, lavender, or pale magenta; less than 1 in. long; borne on slender stems in umbels or forking clusters, each containing from 3 to 12 flowers. Calyx of 5 obtuse sepals; 5 petals; 10 (5 longer,

5 shorter) stamens; 5 styles persistent above 5-celled ovary. Stem: From brownish, scaly bulb 4 to 9 in. high. Leaves: About 1 in. wide, compounded of 3 rounded, clover-like leaflets with prominent midrib, borne at end of slender petioles, springing from root. Preferred Habitat - Rocky and sandy woods. Flowering Season - May-June. Distribution - Northern United States to Rocky Mountains, south to Florida and New Mexico; more abundant southward. Beauty of Leaf and blossom is not the only attraction possessed by this charming little plant. As a family the wood-sorrels have great interest for botanists since Darwin devoted such exhaustive study to their power of movement, and many other scientists have described the several forms assumed by perfect flowers of the same species to secure cross-fertilization. Some members of the clan also bear blind flowers, which have been described in the account of the white wood-sorrel given above. Even the rudimentary leaves of the seedlings "go to sleep" at evening, and during the day are in constant movement up and down. The stems, too, are restless; and as for the mature leaves, every child knows how they droop their three leaflets back to back against the stem at evening, elevating them to the perfect horizontal again by day. Extreme sensitiveness to light has been thought to be the true explanation of so much activity, and yet this is not a satisfactory theory in many cases. It is certain that drooping leaves suffer far less from frost than those whose upper surfaces are flatly exposed to the zenith. This view that the sleep of leaves saves them from being chilled at night by radiation is Darwin's own, supported by innumerable experiments; and probably it would have been advanced by Linnaeus, too, since so many of his observations in "Somnus Plantarum" verify the theory, had the principle of radiation been discovered in his day. The violet wood-sorrel produces two sorts of perfect flowers reciprocally adapted to each other, but on different plants in the same neighborhood. The two are essentially alike, except in arrangement of stamens and pistil; one flower having high anthers and low stigmas, the other having lower anthers and higher stigmas; and as the high stigmas are fertile only when pollenized with grains from a flower having high anthers, it is evident insect aid to transfer pollen is indispensable here. Small bees, which visit these blossoms abundantly, are their benefactors; although there is nothing to prevent pollen from falling on the stigmas of the short-styled form. Hildebrand proved that productiveness is greatest, or exists only, after legitimate fertilization. To accomplish cross-pollination, many plants bear flowers of opposite sexes on different individuals; but the violet wood-sorrel's plan, utilized by the bluet and partridge-vine also, has the advantage in that both kinds of its flowers are fruitful. COMMON, FIELD, or PURPLE MILKWORT; PURPLE POLYGALA (Polygala viridescens; P. sanguinca of Gray) Milkwort family Flowers - Numerous, very small, variable; bright magenta, pink, or almost red, or pale to whiteness, or greenish, clustered in a globular clover-like head, gradually lengthening to a cylindric spike. Stem: 6 to 15 in. high, smooth, branched above, leafy. Leaves: Alternate, narrowly oblong, entire. Preferred Habitat - Fields and meadows, moist or sandy. Flowering Season - June-September. Distribution - Southern Canada to North Carolina, westward to the Mississippi. When these bright clover-like heads and the inconspicuous greenish ones grow together, the difference between them is so striking it is no wonder Linnaeus thought they were borne by two distinct species, sanguinea and viridescens, whereas they are now known to be merely two forms of the same flower. At first glance one might mistake the irregular little blossom for a member of the pea family; two of the five very unequal sepals - not petals - are colored wings. These bright-hued calyx-parts overlap around the flower-head like tiles on a roof. Within each pair of wings are three petals united into a tube, split on the back, to expose the vital organs to contact with the bee, the milkwort's best friend. Plants of this genus were named polygala, the Greek for much milk, not because they have milky juice - for it is bitter and clear - but because feeding on them is supposed to increase the flow of cattle's milk. In sandy swamps, especially near the coast from Maine to the Gulf, and westward to the Mississippi, grows the MARSH or CROSS-LEAVED MILKWORT (P. cruciata). Most of its leaves, especially the lower ones, are in whorls of four, and from July to September its dense, bright purple-pink, white, or greenish flower-heads, the wings awn-pointed, are seated on the ends of the square branching stem of this low, mossy little plant. FRINGED MILKWORT or POLYGALA; FLOWERING WINTERGREEN; GAY WINGS (Polygala paucifolia) Milkwort family Flowers - Purplish rose, rarely white, showy, over 1/2 in. long, from 1 to 4 on short, slender peduncles from among upper leaves. Calyx of 5 unequal sepals, of which 2 are wing-like and highly colored like petals. Corolla irregular, its crest finely fringed; 6 stamens; pistil. Also pale, pouch-like, cleistogamous flowers underground. Stem: Prostrate, 6 to 15 in. long, slender, from creeping rootstock, sending up flowering shoots 4 to 7 in. high. Leaves: Clustered at summit, oblong, or pointed egg-shaped, 1 1/2 in. long or less; those on lower part of shoots scale-like. Preferred habitat - Moist, rich woods, pine lands, light soil. Flowering Season - May-July. Distribution - Northern Canada, southward and westward to Georgia and Illinois. Gay companies of these charming, bright little blossoms hidden away in the woods suggest a swarm of tiny mauve butterflies that have settled among the wintergreen leaves. Unlike the common milkwort and many of its kin that grow in clover-like heads, each one of the gay wings has beauty enough to stand alone, Its oddity of structure, its lovely color and enticing fringe, lead one to suspect it of extraordinary desire to woo some insect that will carry its pollen from blossom to blossom and so enable the plant to produce cross-fertilized seed to counteract the evil tendencies resulting from the more prolific self-fertilized cleistogamous flowers buried in the ground below. It has been said that the fringed polygala keeps "one flower for beauty and one for use"; "one playful flower for the world, another for serious use and posterity"; but surely the showy flowers, the "giddy sisters," borne by all cleistogamous species to save them from degenerating through close inbreeding, are no idle, irresponsible beauties. Let us watch a bumblebee as she alights on the convenient fringe which edges the lower petal of this milkwort. Now the weight of her body so depresses the keel, or tubular petals, wherein the stamens and pistil lie protected from the rain and useless insects, that as soon as it is pressed downward a spoon-tipped pistil pushes out the pollen through the slit on the top on the bee's abdomen. The stigmatic surface of the pistil is on the opposite side of the spoon, nearest the base of the flower, to guard against self-pollination. After the pollen has been removed, a bumblebee, already dusted from other blossoms, must leave some on the stigma as she sucks the nectar. Indeed, every feature possessed by this pretty flower has been developed for the most serious purpose of life - the salvation of the species. Only locally common throughout a wide area, embracing the eastern half of the United States and Canada, is the RACEMED MILKWORT (P. polygama), whose small, purple-pink, but showy flowers, clustered along the upper part of numerous leafy stems, are found in dry soil during June and July. Like the fringed milkwort, this one bears many cleistogamous, or blind flowers, on underground branches, flowers that always set an abundance of fertile self-planted seed in case of failure to form any on the part of their showy sisters, which are utterly dependent upon the bee's ministrations. During prolonged stormy weather few insects are abroad.


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