Deciduous shrub, to 2 m; young twigs densely covered with gland-tipped and/or eglandular multicellular hairs. Leaves 6.5–12(–14.5) × 1.6–3.4(–4.2) cm, ovate or obovate to elliptic, lower surface sometimes glaucous, covered with glandular or eglandular hairs. Flower bud scales glabrous to (occasionally) covered with unicellular hairs, margins glandular. Pedicels densely covered with gland-tipped hairs. Flowers with a sweet fragrance, appearing before or with the leaves, 9–17, in a shortened raceme; calyx 1–4(–7) mm; corolla yellow, with a darker yellow blotch on the upper lobe, funnelform, tube gradually expanding into the limb, outer surface covered with unicellular and gland-tipped hairs, 25–50 mm. Capsule covered with unicellular and gland-tipped hairs. Flowering May-June. Royal Horticultural Society (1997)
Distribution Armenia Azerbaijan Georgia Moldova Poland Russia Abkhasiya, Dagestan Slovenia Turkey Ukraine
Habitat s.l.-2,300 m
RHS Hardiness Rating H6
Awards AGM 1993.
Conservation status Least concern (LC)
Taxonomic note R. luteum may be distinguished from the allied R. austrinum by the yellow flowers with a darker blotch and by the less hairy capsules. Royal Horticultural Society (1997)
A deciduous shrub of vigorous, rather stiff habit, 8 to 10 ft high; young shoots viscous, glandular. Leaves linear-oblong, 21⁄2 to 5 in. long, 3⁄4 to 11⁄2 in. wide;with a short, abrupt tip, more tapering at the base; at maturity glaucous, hairy beneath along the midrib and at the margins; stalk hairy, 1⁄3 in. or less long. Flowers fragrant, rich bright yellow, 11⁄2 to 2 in. across, crowded in several clusters at the end of the previous year’s naked shoots, in May, on sticky, glandular stalks 1⁄2 to 3⁄4 in. long. Calyx-lobes small, ovate, edged with glanded hairs. Corolla-tube 1⁄2 in. long, hairy. Stamens five, hairy at the base like the style. Bot. Mag., t. 433. (s. Azalea ss. Luteum)
Native mainly of the western Caucasus, where it grows from sea-level to the subalpine zone, and of bordering parts of Turkey. In Russia it is also found in the N.W. Ukraine and bordering parts of White Russia, and there is an isolated stand under State protection in Poland (Wola Zarczycka, near Lezaysk). Outposts have also been reported from E. Austria and N.W. Yugoslavia. It was introduced to Britain from the Caucasus by Pallas in 1792 to Lee and Kennedy’s nursery and again by Anthony Hove of Warsaw in 1796.
This beautiful perfectly hardy azalea, the only yellow one known until the advent of R. molle (sinense), and the parent or the predominant parent of all the older yellow garden varieties, is still one of the most useful and generally cul tivated of all shrubs. It blossoms unfailingly, and with an exquisite fragrance. Added to this is its fine autumn colouring, in shades of red, orange and purple. Coming freely from seed, it is the chief stock used for grafting the choicer varieties on. This probably explains its abundance in gardens, for being a vigorous grower it will, unless watched, often send up strong sucker growths that in time smother out the more finely bred sorts grafted on it.
R. luteum produces thickets of self-sown seedlings when grown in grass-free undisturbed soils and has become semi-naturalised in some localities. It is of great phytogeographic interest as the only European azalea, belonging to a subseries which has its headquarters in N. America, but represented in E. Asia also.
In Asiatic Turkey this species is not confined to the north-east: it is fairly widespread along the northern ranges and in western Anatolia. It also occurs, or did, on the Greek islands of Lesbos and Samos.