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.
Slender herbs (in Europe) with angular stems and entire leaves, in whorls of 4, 6, or 8, the buds and branches always opposite. Flowers small, in terminal or rarely axillary heads or panicles. Calyx more or less combined with the ovary. Corolla mono-petalous, with 4 or 5 spreading lobes. Stamens as many, inserted in the tube. Ovary inferior. Style 2-cleft at the top, with a capitate stigma to each branch. Fruit of 2 1-seeded, indehiscent lobes.
One of the largest families, with perhaps 4500 species, but particularly numerous in the tropics, where it includes trees and shrubs as well as herbs.
Herbs with weak, quadrangular stems, sessile leaves in whorls of 4, 6, or 8, and small white, yellow, or reddish flowers in axillary or terminal cymes or panicles. Calyx combined with the ovary without any visible border. Corolla rotate, the tube scarcely perceptible, with 4 spreading lobes. Fruit small, dry, 2-lobed.
A large genus of about 200 species, spread over the whole of the temperate regions, and especially abundant in Europe and Northern Asia, and penetrating into the tropics.
A slender, green species, 6-10 inches high, with stoloniferous, creeping branches and ascending stems, with short internodes. Leaves in fours, oval-elliptic, obtuse or rarely mucronate, with 3 principal nerves. Flowers yellow, on glabrous pedicels, disposed in axillary cymes. Fruit glabrous and shining, becoming blackish. It somewhat resembles the common G, Cruciata, which is also seen in sub-alpine woods and clearings, but vernum is smaller and the leaves broader, and it is much less hairy.
Pyrenees, Corbieres, Cevennes, Alps, Italian Switzerland, and near Brienz, Corsica, Central and Southern Europe, Siberia.
A slender, branched plant, 8-12 inches high. Leaves oval, the inferior often nearly round, delicate, glabrescent, in whorls of 4, feebly 3-nerved. Flowers white, very small, in a trichotomous panicle, loose and spreading, few-flowered, and almost naked. Pedicels divaricate, rather long. Corolla-lobes oval, sub-obtuse. Fruit covered with hooked hairs.
Mountain woods (especially coniferous) and moors. May to July.
Pyrenees, Corbieres, Vosges, Jura, Alps, Cevennes, Corsica. Europe from Scandinavia to the Caucasus, and Asia Minor.
Rootstock woody. Plant glabrous and smooth, except for a slight roughness at edge of leaves. Stems 1-2 feet high, branched, ending in a long panicle of numerous small yellow flowers. [Leaves linear, numerous, in whorls of 6-8. Fruit small, glabrous.
Dry hillsides and pastures from the plains up to the lower Alps, where it is sometimes very robust. June, July.
Europe, Central and Russian Asia, except in the extreme north. British.