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.
Herbs or woody shrubs, often evergreen. Flowers regular, campanulate, 4-5 lobed. Calyx 4-5 fid. Stamens 4-10. Ovary 4-5 celled. Style terminal. Fruit a berry or capsule.
A family of over 1000 species, spread over the whole globe, but particularly on siliceous soil.
Shrubs with alternate and often large leaves. Flowers large, handsome, and usually red, often irregular. Sepals and corolla-lobes usually 5. Stamens usually 10.
Plate. XXXIII. Rhododendron Among Granite Boulders Above Argentiere.
About 200 species in Europe, Central Asia, Malay, and North America.
An erect, branched shrub. Leaves elliptical, ovate or obovate, finely crenate, more or less ciliate, otherwise glabrous, evergreen, shining and bright green above, dotted on under side with scattered, resinous, at first yellowish, finally rusty brown glands. Flowers in terminal corymbs, nodding on erect flower-stalks. Corolla funnel-shaped, a beautiful rose colour, rather paler than in the next, dotted on the outside with resinous glands like the flower-stalk, calyx, and ovary.
Rocky places and steep mountain-sides in the limestone Alps and sub-Alps up to over 7000 feet, and descending occasionally to the valleys, as, e.g. St. Margrethen in the Rhine Valley, and the banks of Lago Maggiore. Not found in the Jura. June, July.
Carpathians, Eastern, Central, and Western Alps. But only on Mont Chauffe in the French Alps, where it was discovered in 1904. Southern Germany.
A similar-sized shrub. Leaves lanceolate to elliptical, entire, or sometimes finely crenate, glabrous, dark green and shiny above, somewhat revolute at the margin, coriaceous, evergreen, covered on under side when young with densely packed yellowish resinous, finally coalescent glands, turning rusty brown when older. Flowers in terminal corymbs, more or less erect on longer flower-stalks than in the last. Corolla rose-coloured (very rarely white), dotted on the outside with resinous glands like the glabrous flower-stalk, calyx and ovary. Leaves of the previous year cinnamon-brown in colour. Leaves more crowded than in hirsutum.
Similar habitats, but usually, though not always, on primary rocks. June, July. It ascends to 8800 feet in Valais, and descends to the plain in Tessin, and is occasionally found as a glacier relic in turbaries in woods of the Swiss plateau.
Carpathians, Eastern, Central, and Western Alps; Jura, Pyrenees, Apennines, Spain, Transylvania.
The white-flowered variety is very rare; the specimen figured was found by Mr. Flemwell near the Planet above Argentiere in Haute-Savoie.
This Rhododendron can be grown in the garden in a mixture of sand and peat, from well-established plants, in a sheltered and somewhat cool position.
A small, prostrate, under-shrub, not exceeding 6 inches in height, with ascending branches. Leaves very small, elliptic-lanceolate, more or less serrate, ciliated, otherwise glabrous, coriaceous, evergreen, grass-green on both sides, shining, not dotted, cilia often glandular. Flowers in clusters of 1-3, on long stalks, erect, rotate or expanding, rose-coloured, very deciduous. Calyx-teeth lanceolate, acute, reddish purple. Anthers purple-black.
Abundant, but local, in stony Alpine and sub-Alpine places, on limestone, but not making such a feature in the landscape of the Eastern Alps as the other species, the flowers being paler, and the leaves appearing only after the flowers. May to July.
Carpathians, Eastern Alps from Tyrol to Carniola, 4000-5000 feet. A partially shaded place suits it best.
To succeed in the sun with it, the plant must be well established before planting out, or it must be shaded from the sun by artificial means; then it will bloom much more freely than in a shady place.
Hard peat and sand should be pressed firmly against the roots, and it should be top-dressed twice a year with the same compost. (W. A. Clark).