Rhododendron Cultivars N

'Nancy Waterer'

Soft rich yellow, 2 in. wide, with a deeper flare (A. Waterer, Knap Hill; in commerce 1880). A beautiful, vigorous azalea, which received no award when it first appeared but has now been recommended for an Award of Garden Merit. It is usually classed as a Ghent, but is probably one of the first results of the elder Anthony Waterer’s attempts to improve the Ghents by crossing them with R. molle (Azalea sinensis).

'Naomi'

Flowers 10 in the truss. Corolla funnel-shaped with a narrow tube, 33⁄4 in. wide, 7-lobed, soft lilac mauve shading to greenish yellow in the tube, where there are faint brownish crimson markings. Style glandular at the base. Leaves elliptic to oblong-obovate, 61⁄4 by 23⁄4 in., obtuse. A.M. 1933.

'Naomi'

Corolla 21⁄4 in .wide, soft salmon-pink, paler in the centre, slightly speckled with red on the upper lobes. Open habit, to 5 or 6 ft eventually. Late May or early June. A hybrid of R. kaempferi raised at Exbury. It is quite hardy, with flowers of an unusual and attractive colour.

Naomi (Aurora × fortunei)

This famous Exbury hybrid is the result of mating R. fortunei with a hybrid which is itself one-quarter R. fortunei, and shows the influence of that species in the form of the corolla, which is basically funnel-shaped but usually with a pronounced tube; in the delicate pink colouring of some of the clones and also the yellowish ground-colour of many of them, which shows up in the tube especially; in the fragrance of the flowers; and in hardiness of the plants. R. griffithianum, working in its usual unobtrusive way, has enlarged the corolla and, with R. fortunei, raised the number of lobes to six or seven. The form of the truss is also the contribution of these two species. R. thomsonii is responsible for the deeper pink colouring of some of the clones, such as ‘Naomi Glow’ and, with R. griffithianum, for the usually pronounced calyx; some clones also show its influence in their relatively broad leaves.

The following are the best known clones: ‘Naomi’, ‘Exbury Naomi’, ‘Naomi Glow’, ‘Naomi Nautilus’, ‘Naomi Stella Maris’, ‘Naomi Pink Beauty’.

The Naomi clones are hardy, and flower at the end of April or in May. The original plants at Exbury are now 15 to 18 ft high and almost as much in spread, furnished to the ground. Many are depicted in Rothschild Rhododendrons, pls. 12, 14, 64.

'Naomi Glow'

Flowers 10 in the truss. Corolla 31⁄4 in. wide, 6– or 7-lobed, vivid pink with crimson markings in the throat. Style stout, glandular to the tip. Leaves oblanceolate, obtuse, 61⁄2 by 23⁄4 in.

'Naomi Nautilus'

Corolla widely spreading, frilled, 4 in. wide, rose passing to cream in the centre. Leaves obovate, obtuse, 51⁄2 by 21⁄2 in. A.M. 1938.

'Naomi Pink Beauty'

Corolla of a beautiful shade of pink, shading slightly to creamy pink at the centre, with some crimson markings in the tube.

'Naomi Stella Maris'

This is apparently rather similar to ‘Naomi Nautilus’, but was not properly described when it received an F.C.C. in 1939.

'Narcissiflora'

Flowers double, well formed, beautiful soft yellow, 11⁄2 in. wide, with a tube 1 in. long. Narrow habit. Bronze autumn colour. A fine azalea of unique colouring, excellent for the small garden. It is a Ghent, near to R. luteum, raised by L. van Houtte, before 1871. F.C.C. 1879. F.C.C.T. May 29, 1923,‘Bartholo Lazzari’Is similar but not so good.

'Nellie'

Flowers about twelve in a hemispherical truss, on glandular pedicels. Corolla funnel-shaped with a narrow tube, almost 21⁄2 in. wide, with a large yellow blotch, glandular on the outside, lobes wavy and somewhat recurved. Stamens ten. Leaves semi-deciduous, up to 4 in. long and 11⁄2 in. wide. June. Raised by Harry White at the Sunningdale Nursery. Probably R. occidentale is the azalea-parent.

'New Moon'

Flowers 11–12 in the truss. Corolla funnel-shaped from a broad base, 6-lobed, pale pink in the bud, flushed with pink when first open, becoming white, tinged with yellow in the upper part of the throat and with slight streaking there. Style almost straight, with a small green stigma. May. (fortunei × campylocarpum hybrid; Slocock. A.M.T. 1953.)

'Nimbus'

Flowers fragrant, about eight in the truss; rachis 21⁄2 in. long. Corolla 7-lobed, funnel-shaped from a broad base, 4 in. wide, pure white when fully expanded. Leaves elliptic, leathery, 71⁄2 by 3 in. Vigorous, upright habit. Late May or early June. (‘Snow Queen’ × Cornish Loderi; Waterer, Knap Hill. F.C.C.T. 1967.) Cornish Loderi is the same cross as Angelo, i.e., R. discolor × R. griffithianum.

Nobleanum (arboreum × caucasicum)

This well-known cross unites the great Himalayan tree rhododendron with the dwarf R. caucasicum from the Caucasus and bordering parts of Turkey. The cross was made many times, with differing results, according to what forms of the species were used. Since the original ‘Nobleanum’ is known only from the portrayal of a single corolla it is best to give a generalised description. Flowers twelve to twenty in a compact truss, opening during winter or early spring, sometimes as early as December; rachis up to 1 in. or slightly more long; bud-scales more or less persistent at flowering time; pedicels up to 1 in. or slightly more long, usually glandular and downy. Corolla funnel-shaped or funnel-campanulate, about 2 in. wide, sometimes larger, variable in colour from deep crimson to light pink, or bicoloured pink or white (or wholly white in the forms deriving from white-flowered R. arboreum). The corolla is always in some degree speckled – either on the lobes (mainly on the upper lobes), or in other forms below the sinuses. Ovary white-felted; style glabrous with a crimson or brownish-crimson stigma. Leaves elliptic, oblong or oblanceolate, 5 to 7 in. long, variable in width, dull medium or dark green above, underside clad with a thin brown tomentum or, in at least one clone, burnished silver. The habit is as variable as the flowers and foliage, some forms being low and dense, others tall-growing.

The first recorded cross between R. arboreum and R. caucasicum was made in 1829 by William Smith of Norbiton, using the latter species as the seed-parent. One plant flowered in 1835 when 8 in. high, and was described and figured by Sweet under the name R. venustum (Brit. Fl. Gard., 2nd series, t. 285). The flowers were rich pink, paler at the edge, marked all over with red spots, with ‘wavy and crumpled’ lobes. In the same year two forms from the same cross, made at the Knap Hill Nursery, were figured in Bot. Reg., t. 1820. The plate is mainly devoted to a form named by Lindley R. pulcherrimum, with pink corollas fading to paler at the centre, and pink spotting on the upper lobes. The plant named R. Nobleanum is represented on the same plate by a single corolla, described as ‘deep and brilliant rose’. The history of this famous name, as given by Gerald Loder, is as follows: ‘The older Anthony Waterer used to tell the story of how one day when he was a boy J. C. Loudon and a Mr Noble were paying his uncle Michael Waterer a visit, [and] he was sent from the lunch table for a truss of a hybrid rhododendron just then in flower for the first time. It was there and then named R. Nobleanum, but whether the gentleman was connected with then firm of Standish and Noble is not known.’ (Rhodo. Soc. Notes, Vol. II, p. 252.) It may be added that the firm of Standish and Noble did not exist at that time; the visitor is hardly likely to have been Standish’s future partner Charles Noble, who did not retire until 1898.

There can be no doubt that the cross was made by other nurserymen. The best forms have been propagated vegetatively, but seedlings were also sent out. According to a letter preserved at Kew, the firm of Cunningham and Fraser used to repeat the cross whenever they needed a new stock of plants for sale, using the red-flowered or white-flowered R. arboreum according to which form of Nobleanum was required. Whether the original clone of Nobleanum is still in commerce it is impossible to say, as the name soon came to be used in a collective sense. As for R. venustum, Sweet said that Smith had a good stock of it, which can only have meant that he had plenty of seedlings from the cross. Another of the Smith seedlings, then 1–2 ft high and grown by the nurseryman Rollisson, was named R. caucasico-arboreum by Maund and Henslow in 1840 (Maund’s Botanist, Vol. IV, t. 157). It was similar to the type, but clearly not the same. The hybrid commonly grown as ‘Nobleanum Venustum’ at the present time has corollas with inconspicuous spotting, pink paling to white at the centre. It makes a low spreading shrub up to 6 ft high and often starts to flower in December. A hybrid grown in Cornish gardens as ‘Nobleanum Venustum’ is again different. It is discussed by Millais in Rhododendrons (1917), p. 119. Two plants at Kew received originally as R. venustum agree with the type in having the corollas distinctly speckled but represent two different clones. However, there is really no reason why all these different forms should not descend from one or other of the Smith seedlings.

The common white-flowered form of Nobleanum has narrow leaves and rather small flowers with greenish-yellow spotting. ‘Heatherside Beauty’, of uncertain parentage, is to be preferred as an early-flowering hardy white.

A rhododendron whose flowers are produced in the dead of winter and are destroyed by frost more often than not might seem to have little claim to a place in gardens. Yet Nobleanum received an Award of Garden Merit in 1926 and few rhododendrons are better known to the public at large. Unlike many other early-flowering rhododendrons it is perfectly hardy and growths are produced late enough for them to escape damage by frost in most seasons. Also, the flowers open over a long period, so even if most of the trusses are spoilt, some will usually escape. If the weather be exceptionally favourable, no tree gives such a brilliant display in the first two months of the year, and for this reason a few examples are worth growing. If possible, a spot sheltered by trees from the north and east should be given them.

See also ‘Jacksonii’ and ‘Christmas Cheer’.

Note. Nobleanum is used here as the name for the R. arboreum × R. caucasicum hybrids since it is the established name and is accepted by the International Register. The correct botanical name, however, is R. × pulcherrimum Lindl. (syns. R. venustum Sw. (1835), not Salisb. (1796); R. caucasico-arboreum Maund and Henslow). Rehder adopts R. caucasico-arboreum, on the grounds that the name R. pulcherrimum, though published earlier, is not supported by a botanical description.

Rhododendron Nobleanum grex at the Royal Botanic Garden Edinburgh, UK. 6 February 2022. Image Tom Christian.

Identified as Rhododendron 'Nobleanum' at Bedgebury National Pinetum, Kent, UK, this example of the group shows indumentum derived from the R. arboreum parent on the underside of its leaves (February 2026). Image John Grimshaw.

A pale-flowered member of the Nobleanum Group at Bedgebury National Pinetum, Kent, UK (February 2026). Image John Grimshaw.

'Noordtianum'

Named clone in the Mucronatum group. Introduced to Belgium towards the end of the last century. It has larger flowers and leaves than ordinary Mucronatum and narrow, acute calyx-lobes 3⁄4 in. long. For further details, see K. Wada’s note in R.C.Y.B. 1968, pp. 144–5.

'Norma'

Double, buff-pink, the upper lobe in some flowers marked with a slight orange flare; petaloids also buff-pink, but sometimes white with a yellow stain, both colours occurring in the same truss (Rustica fl.-pl.; Vuylsteke). A.M.T. 1959. In the year the award was given, the plant in the trials was flowering from May 9, but the usual flowering time for ‘Norma’ is mid- to late May. It is vigorous and very free-flowering.

Norman Shaw ('B. de Bruin' × discolor)

'Nutmeg'

A clone of the same parentage as ‘Arthur Osborn’ is ‘Nutmeg’.