Polygala

Polygala is a large genus of flowering plants belonging to the family Polygalaceae. They are commonly known as milkworts or snakeroots. The genus is distributed widely throughout much of the world in temperate zones and the tropics. The genus name Polygala comes from the ancient Greek 'much milk', as the plant was thought to increase milk yields in cattle. Polygala includes annual and perennial plants, shrubs, vines, and trees. The roots often have a scent reminiscent of wintergreen. The leaf blades are generally undivided and smooth-edged, and are alternately arranged in most species. The inflorescence is a raceme or spikelike array of several flowers; the occasional species bears solitary flowers. The flower is bilateral in shape, with two large petal-like sepals on the sides, often called the 'wings', and three smaller sepals behind. There are three petals in shades of reddish purple, yellow or white, which are joined at the bases. The lower of the three is the keel petal, which is 'boat-shaped, cucullate , or helmet-shaped'. The keel petal may have a beak or a fringe on the tip. Stamens and style are within the curve of the keel petal. The fruit is a capsule, sometimes winged. It contains two seeds, which are usually black, hairy and tipped with a large white aril. One polygala is the Fringed Polygala, found in coniferous forests. Polygala species are used as food plants by the larvae of some Lepidoptera species including large grizzled skipper. Some species are valued in cultivation. The hybrid evergreen shrub P. × dalmaisiana (P. myrtifolia × P. oppositifolia) has gained the Royal Horticultural Society's Award of Garden Merit. The reported number of valid species in the genus varies from about 350 to 500 to 725 or 730. The Americas have the most species, especially South America, with Africa second in diversity and Asia third. Species include: