This section is from the book "Sub-Alpine Plants Or Flowers Of The Swiss Woods And Meadows", by H. Stuart Thompson. Also available from Amazon: Sub-Alpine Plants: Or, Flowers of the Swiss Woods and Meadows.
A family represented in Europe only by Polygala itself. The other genera being chiefly tropical and differ from Polygala in the form of the fruit, or, in minor details, in the structure of their flowers.
Herbs or shrubs, with entire leaves, usually alternate, no stipules, and very irregular flowers in terminal racemes. Sepals 5, of which the two inner are larger, usually petal-like, and commonly called wings. Petals 3, 4, or 5, the lowest very small and subulate, and all more or less united with the stamens. Stamens united in two parcels. Style 1, with a single stigma. Ovary and capsule flat, 2-celled, with a single pendulous seed in each cell.
A numerous genus, widely spread over most parts of the globe. Some of the showy S. African species are often cultivated in our greenhouses.
Stem shrubby, creeping, branched; branches prostrate or ascending, glabrous like the whole plant. Leaves narrowly lanceolate or elliptical, entire, mucronate, the lower ones smaller, obovate. Flowers solitary or in pairs, terminal, or in the axils of the leaves. Corolla with a small, 4-lobed crest, as long as or shorter than the wing-sepals, which are ovate, oblique, erect or recurved, nerveless, with branched veins. Wings pale yellow before fertilization, often red, brownish or purple later. Corolla tube deep yellow, but purplish after fertilization.
Woods and rocky or grassy places in the mountains, extending up to the Alpine region, where it is usually dwarfer and more floriferous. Very common. A difficult plant to get up by the long, slender roots, for they penetrate long distances, and yet there is little of them to survive a journey to this country. May to July.
Central Europe from the Eastern Pyrenees to Roumania. Rare in the Jura.
This evergreen creeping shrub likes a shady place in sandy peat and loam, or in good leaf mould, and can be increased when well established by careful division.
A small species, 2-4 inches high, with branched, recumbent stems. Leaves oboval or oblong, forming a rosette; stem-leaves narrower and much smaller. Flowers pale blue, very small, in small, dense, terminal heads. Capsule small, rather shorter, but broader than the wings.
Mountain pastures; local. June, July.
Western Alps, including Southern Switzerland, Pyrenees.
Stems numerous, woody, filiform, spreading, ascending. Lower leaves short, broadly ovate, often forming a rosette; upper leaves longer, clothing the lower part of the panicle. Flowers small, pale blue. Wings of calyx ovate, as broad as, and longer than the capsule.
Alpine and sub-alpine pastures, especially on limestone. June, July.
Juras, Central and Western Alps, including Piedmont.
This species is not much understood, and is often confused with P. alpina Perr. et Long. P. alpestris may perhaps be a form of P. amara L., and it is synonymous with P. amarella Crantz var. alpestris Borbas.
For the rock-garden there are other more beautiful species than the above which, though not Alpine, are more worthy of a place on rockeries. P. nicaeensis Risso, a Mediterranean plant extending into the Maritime Alps up to 2000 feet, has handsome purple flowers. The Common Milkwort P. vulgaris L., with flowers of blue, rose, purple, or white, attains a remarkable size in the mountains, and is well worth more attention in our gardens, for it will grow anywhere and is very pretty.