Dwarf shrub, 0.3–1 m; young shoots sparsely tomentose; bud scales deciduous. Leaves 4–7.5 × 1.3–3 cm, obovate to elliptic, apex blunt to apiculate, upper surface glabrous, lower surface covered with a compacted fawn to brownish tomentum composed of dendroid hairs; petioles sparsely velutinous. Flowers 6–15, in a lax to dense truss; pedicels to 30 mm in flower, elongating in fruit to 60 mm; calyx 2–3 mm; corolla whitish to yellow, sometimes flushed with pink, with greenish flecks, broadly campanulate, nectar pouches lacking, 30–35 mm; ovary densely dendroid-pilose, style glabrous. Flowering April-May. Royal Horticultural Society (1997)
Distribution Georgia Turkey NE
Habitat 1,800–2,700 m
RHS Hardiness Rating H7
Conservation status Least concern (LC)
Taxonomic note The hybrid R. × sochadzeae Char & Davlianidze (R. caucasicum × R. ponticum) is occasionally seen in cultivation. It occurs in the wild where the two species grow together. Royal Horticultural Society (1997)
An evergreen, low shrub, usually under 3 ft in height, with slightly downy young shoots. Leaves sometimes rather leathery, glabrous and dark green above, more or less clothed with brownish-red felt beneath; narrowly oval or slightly obovate, 2 to 4 in. long, 3⁄4 to 11⁄2 in. wide; stalk stout, 1⁄4 in. long. Flowers yellowish white or pink-tinged, spotted in the upper part of the throat, borne in May in candelabroid trusses; bud-scales slow to fall. Corolla 2 in. wide, funnel-campanulate, wavy-edged; stamens ten; calyx very small; flower-stalk slightly downy, about 11⁄2 in. long; seed-pods erect. Bot. Mag., tt. 1145 and 3422. (s. Ponticum ss. Caucasicum)
Native of the Caucasus, Russian Armenia, and north-eastern Asiatic Turkey, forming a dense scrub at or above the timber-line; introduced in 1803. Although its hybrid progeny is numerous in gardens, the true species is itself now scarcely ever seen. It is an interesting dwarf bush, remarkable for its dense habit and slow growth. Since it approaches 9,000 ft in the wild it is perfectly hardy in this country and flowers when quite young. It was reintroduced by Apold, Cox, and Hutchison from Turkey in 1962 (R.C.Y.B. 1963, pp. 66–7).
R. caucasicum is the parent of many hardy, early-flowering hybrids, of which the best-known are the crosses with R. arboreum and their offspring (grex Nobleanum). Others are of more complex origin. Some of these hybrids show the influence of R. caucasicum in their erect, clustered peduncles and persistent bud-scales. In some the finely impressed venation of the leaf of R. caucasicum is also evident.
The hybrid status of R. nikomontanum is accepted by Dr Chamberlain.
R. chrysanthum Pall