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Journal American Rhododendron Society

Current Editor:
Dr. Glen Jamieson ars.editor@gmail.com


Volume 34, Number 4
Fall 1980

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Two New Rhododendron Species And A New Variety
H. H. Davidian, Edinburgh, Scotland

Rhododendron grothausii Davidian, sp. nov.
        Species R. lindleyi Moore affinis sed corolla minore 5.3-7.5 cm. longs, foliis plerumque minoribus supra bullatis, alabastro rubro-brunneo recedens.
        Frutex nonnunquam epiphyticus 1.22-4.58 m. altus; ramuli moderate vel dense lepidoti, esetulosi. Foliorum lamina coriacea, oblongs vel oblongolanceolata, 6.5-11.5 cm. tongs, 2.84.4 cm. lata, spice rotundata vel obtusa et mucronata, basi rotundata vel obtusa, supra atroviridis nitens bullata lepidota vel elepidota, costs media sulcata, venis primariis 8-10 impressis, margine esetulosa, infra glauca, squamis inaequalibus mediocris vel magnis brunneis inter se 2-4 diametris distantibus praedita, costs media prominente, venis primariis elevatis; petiolus 1-2 cm. longus, supra convexus haud sulcatus, dense vel moderate lepidotus, esetulosus. Inflorescentia terminalis umbellata, alabastris rubro-brunneis, 3-8-flora; rhachis 2-5 mm. longs, lepidota, esetulosa; pedicelli 0.8-1.8 cm. longi, crassi, dense lepidoti, esetulosi. Calyx 5-lobatus, 1-1.5 cm. longus, pallide viridis vel viridis vel roseus, lobis oblongis vel ovalibus, extra elepidotis vel raro basi sparsim lepidotis, glabris, margine moderate vel raro dense ciliatis. Corolla anguste tubuloso-campanulata vel tubuloso-campanulata, Paulo ventricosa, 5.3-7.5 cm. longs, 5-lobs, lobis rotundatis margine interdum emarginatis, fragrans, alba vel ochroleuca vel pallide roses vel rosea, basi aurantiaci-vel lutei-notata, extra elepidota vel tubi basim versus lepidota vel raro omnino lepidota, glabra. Stamina 10 inaequalia, 3-5.2 cm. longs, corollae breviora; filaments in pane quarts vel triente inferiore dense pubescentia; anthers 4-5 mm. longs. Ovarium oblongum spice in stylum contractum, 8-9 mm. longum, 5-loculare, dense lepidotum, glabrum; stylus rectus vel dimidio superiore curvatus, 3-5.5 cm. longus, corollae brevior, in pane quarta vel triente inferiore lepidotus, stigmate 4 mm. diametro discoideo. Capsula oblongs, 4-4.4 cm. longs, 1.3-1.5 cm. lata, recta vel Paulo curvata, costata, dense lepidota, glabra, calyce persistente.
        S. TIBET. Migyitun. Tsari Chu. (See No. 1702). Just below where 1702 was collected, this rhododendron is common. A shrub 4-15 ft. sometimes epiphytic on trees, usually hanging over cliffs or river banks. Very fragrant. Corolla white, orange patch at base; calyx green; filaments white, anthers brown, style and stigma green. Flowers are mostly over now. Altitude 8,500 ft. 28. 5.1936. F. Ludlow & G. Sherriff No. 1715 (Holotype in Herb. Brit. Mus.).
        S. BHUTAN. Jirgang Chu, S. Ridge. Epiphytic shrub 6-10 ft.; flowers terminal 2-3; corolla lobes pure white, slightly pale golden at base of tube inside. Filaments hairy at base, white, anthers brown. Style glabrous, tinged red. Calyx dull red, glabrous, fringed with white hairs. No indumentum on leaves. Very fragrant. On trees in dense wet forest. Altitude 8,500 ft. 3. 5.1937. F. Ludlow & G. Sherriff No. 2980.
        BHUTAN. Saga La, near Drugye Dzong. Shrub 5 ft. in Tsuga forest. Calyx green, suffused pink; corolla cream, yellowish at base inside. Altitude 9,000 ft. 10. 5.1949. F. Ludlow, G. Sherriff & J. H. Hicks No. 16184. This plant has for long been confused with R. lindleyi. It was discovered by Ludlow and Sherriff in March 1936 at Migyitun, Tsari Chu, South Tibet. They found it again later in Bhutan, and with Hicks in another locality also in Bhutan. It grows hanging over cliffs or river banks, and in Tsuga forest, sometimes as an epiphyte on trees, at elevations of 2,593-2,745 m. (8,500-9,000 ft.). Ludlow and Sherriff record it as being common at Migyitun, South Tibet at 2,593 m. (8,500 ft.).
        R. grothausii is a member of the Megacalyx Subseries, Maddenii Series. It is allied to R. lindleyi from which it differs markedly in that the corolla is smaller 5.3-7.5 cm. long, the leaves (laminae) are usually smaller, bullate on the upper surface, and the flower bud is reddish-brown turning crimson purple later.
        It was introduced by Ludlow and Sherriff in 1936. In cultivation it has proved hardy outdoors along the west coast, and flourishes in several gardens. A remarkable collection of the species is found at Glenarn, Rhu, Dunbartonshire, in the garden of the Gibson family. Along the east coast it is well represented in Mr. and Mrs. Hamish Gunn's greenhouse, at Colinton, Edinburgh. In its native home it grows 4-15 feet high; in cultivation it is broadly upright up to 6 or 7 feet, usually with oblong leaves. One of its chief merits is that it flowers at an early age when raised from seed and cuttings. The species is a late-flowerer, the flowers appearing in May or June. It is free-flowering, and is of great beauty with its tubular-campanulate flowers in trusses of three to eight. The species was given an Award of Merit for a form 'Geordie Sherriff' when shown by Messrs. A. C. and J. F. A. Gibson, Glenarn, Rhu, Dunbartonshire, in 1969.
        The species is named after Mr. & Mrs. Louis C. Grothaus, Lake Oswego, Oregon, U.S.A. as a tribute to their remarkable contributions to the cultivation of rhododendrons, and in appreciation of Mrs. Molly Grothaus's significant achievements as editor of the American Rhododendron Society's Quarterly Bulletin.
        A broadly upright or upright shrub, sometimes epiphytic, 1.22-4.58 m. (4-15 ft.) high; branchlets moderately or rather densely scaly, not bristly. Leaves oblong or oblong-lanceolate, lamina coriaceous, 6.5-11.5 cm. long, 2.8-4.4 cm. broad, apex rounded or obtuse, mucronate, base rounded or obtuse; upper surface dark green, shining or somewhat shining, bullate, scaly or not scaly, midrib grooved, primary veins 8-10 on each side, deeply impressed; margin not bristly; under surface glaucous, laxly scaly, the scales unequal medium-sized or large, brown or dark brown, 2-4 times their own diameter apart, midrib prominent, primary veins raised; petiole 1-2 cm. long, convex, not grooved above, densely or moderately scaly, not bristly. Inflorescence terminal, umbellate, flower-bud reddish-brown (the upper half of the bud-scales) turning crimson purple later, 3-8-flowered; rachis 2-5 mm. long, scaly, not bristly; pedicel 0.8-1.8 cm. long, thick or somewhat thick, rather densely scaly, not bristly. Calyx 5-lobed, 1-1.5 cm. long, pale green, green or pink, lobes oblong or oval, outside not scaly or rarely sparsely scaly at the base, glabrous, margin moderately or rarely densely fringed with white hairs. Corolla narrowly tubular-campanulate or tubular-campanulate, slightly ventricose, 5.3-7.5 cm. long, 5-lobed, lobes rounded, emarginate or not emarginate, margins of the lobes entire, fragrant, white, or white tinged pink on a few petals, or cream, or pink, with a yellowish-orange or orange or yellowish blotch at the base, outside not scaly or scaly at the base of the tube or rarely scaly all over the outside, glabrous outside. Stamens 10, unequal, 3-5.2 cm. long, shorter than the corolla; filaments densely hairy in the lower 1/4-1/3 their length; anthers 4-5 mm. long. Ovary oblong, tapered into the style, 8-9 mm. long, 5-celled, densely scaly, glabrous; style straight or curved in the upper part, 3-5.5 cm. long, shorter than the corolla, scaly in the lower 1/4-1/3 its length, stigma 4 mm. in diameter, disc-like. Capsule oblong, 4-4.4 cm. long, 1.3-1.5 cm. broad, straight or slightly curved, ribbed, rather densely scaly, glabrous, calyx-lobes persistent.

Rhododendron goreri Davidian, sp. nov.
        Species R. nuttallii Booth affinis sed foliis supra pallide viridibus haud bullatis vel aliquanto bullatis, infra pallide viridibus haud rugosis vel paulo rugosis, venis primariis haud valde elevatis haud curvatis haud ramosis, foliis juvenilibus pallide viridibus, corolla minore, pedicellis et calycibus extra glabris, staminibus brevibus, antherio parvis differt.
        Frutex vel arbor 1.22-4.58 m. altus, cortice atropurpurea, ramulis dense lepidotis, squamis magnis. Foliorum lamina coriacea, elliptica, oblongo ovalia, oblongo-elliptica vel ovatooblonga, 14.5-24.5 cm. longs, 5.8-12 cm. lata, spice rotundata vel obtusa et mucronata, basi obtusa vel rotundata, supra pallide viridis, haud bullata vel aliquantum bullata, reticulata, nitens, lepidota vel elepidota, costs media sulcata, venis primariis 14-18 impressis, infra pallide viridis, haud rugosa vel paulo rugosa, squamis inaequalibus mediocris et magnis brunneis inter se '/s-1 diametris distantibus praedita, costs media prominente, venis primariis tenuibus vel crassis elevatis, haud curvatis haud ramosis; petiolus 2-3.1 cm. longus, crassus, supra convexus haud sulcatus, dense lepidotus squamis magnis. Inflorescentia terminalis umbellata 3-5-flora; rhachis 3-5 mm. longs, lepidota; pedicelli 2.8-3 cm. longi, sub fructu multo elongatis, crassi lepidoti glabri. Calyx 5-lobatus, 1.6-2 cm. longus, viridis, lobis oblongo-ovalibus vel ovalibus 7-9 mm. vel raro 1.2 cm. latis, extra lepidotis squamis magnis, glabris, margine eciliatis. Corolla tubuloso-campanulata, 7-7.6 cm. longs, carnosa, 5-lobs, ochroleuca, basi lutei-notata, extra lepidota glabra; lobi rotundati margine paulo crispi. Stamina 10 inaequalia, 3.6-4.3 cm. longs, corollae-tubo breviora; filamenta triente inferiore dense pubescentia; anthers 2-3 mm. longs. Ovarium ovatum spice in stylum contractum, 8-9 mm. longum, 5-loculare, dense lepidotum, glabrum; stylus rectus vel dimidio superiore curvatus, 4.8-5 cm. longus, corollae brevior, triente vel dimidio inferiore lepidotus, stigmate 5-6 mm. diametro discoideo. Capsula oblongs, 4-5 cm. longs, 1.3-2 cm. lata, paulo curvata vel recta, dense lepidota, glabra, calyce persistente.
        S. E. TIBET. Trulung, Pome Prov. Tree 10-15 ft. Not yet in flower. Seed collected. In dense mixed forest. Altitude 7,000 ft. 10 January 1947. F.
Ludlow, G. Sherriff, & H. H. Elliot No. 12117.
        S. E. TIBET. Dem, Po-Tsangpo Valley. Flowers creamy-white, yellowish at base internally; filaments yellow, anthers brown. Style yellow. Calyx green. Altitude 7,500 ft. 3 June 1947. F. Ludlow, G. Sherriff, & H. H. Elliot No. 13077 (Holotype in Herb. Brit. Mus.).  This species was first found by Ludlow, Sherriff and Elliot in January 1947 at Trulung, Pome province, South-east Tibet. It was collected by them again in June of the same year in the Po-Tsangpo Valley in the same region. The plant grows in dense mixed forest at elevations of 2,1352,288 m. (7,000-7,500 ft.).
        R. goreri is a distinctive species and belongs to the Megacalyx Subseries, Maddenii Series. It resembles R. nuttallii in some features, but differs markedly in that the upper surface of the leaf is pale green, not bullate or somewhat bullate, the lower surface is pale green, not wrinkled or slightly wrinkled, the primary veins are not markedly raised, not looped and not branched, the young growths are pale green, the pedicel and the outside of the calyx are not pubescent, the corolla is smaller, the stamens are shorter, and the anthers are smaller.
        The species was introduced by Ludlow, Sherriff and Elliot in 1947 (No. 12117). In its native home it is a shrub or tree up to 15 feet high; in cultivation it is a lax upright shrub and grows up to 5 feet. The plant is tender, and is suitable for a cool greenhouse. It is a robust grower, and makes a fine show with its tubular-campanulate flowers in trusses of three to five. The species received an Award of Merit when exhibited by the Sunningdale Nurseries in 1955 (as R. nuttallii).
        I have named this species after Mr. G. E. Gorer, Sunte House, Haywards Heath, Sussex, in recognition of his great contributions to the cultivation of rhododendrons, including the species of the Maddenii Series.
        A lax upright shrub, or tree, 1.22-4.58 m. (4-15 ft.) high; older stem and branches with dark purplish bark; branchlets rather densely scaly with very large scales, not bristly. Leaves elliptic, oblong-oval, oblong-elliptic or ovate-oblong, lamina coriaceous, 14.5-24.5 cm. long, 5.8-12 cm. broad, apex rounded or obtuse, mucronate, base obtuse or rounded; upper surface pale green, (young growths pale green), not bullate or somewhat bullate, reticulate, somewhat shining, scaly or not scaly, midrib grooved, primary veins 14-18 on each side; deeply impressed; margin not bristly; under surface pale green, not wrinkled or slightly wrinkled, densely scaly, the scales un-equal, small, or medium-sized and large, with widely scattered large scales, brown or dark brown, 1/2 to their own diameter apart, midrib prominent, primary veins thin or thick, raised, not looped and not branched; petiole 2-3.1 cm. long, thick, convex, not grooved above, densely scaly with very large scales, not bristly. Inflorescence terminal, umbellate, 3-5-flowered; rhachis 3-5 mm. long, scaly, not bristly; pedicel 2.8-3 cm. long, lengthening considerably in fruit, very thick, scaly, glabrous, not bristly. Calyx 5-lobed to the base, 1.6-2 cm. long, green, lobes oblong-oval or oval, 7-9 mm. or rarely 1.2 cm. broad, outside scaly with very large scales, glabrous, margin eciliate. Corolla tubular-campanulate, 7-7.6 cm. long, fleshy, 5-lobed, lobes rounded, margins slightly crinkled, creamy white, yellowish at the base of the tube within, scaly all over the outside, glabrous outside. Stamens 10, unequal, 3.6-4.3 cm. long, shorter than the corolla-tube; filaments densely hairy in the lower their length; anthers 2-3 mm. long. Ovary ovate, tapered into the style, 8-9 mm. long, 5-celled, densely scaly, glabrous; style straight or curved in the upper part, 4.8-5 cm. long, shorter than the corolla, scaly in the lower 1/s-'/z its length, stigma 5-6 mm. in diameter, disc-like. Capsule oblong, 4-5 cm. long, 1.3-2 cm. broad, slightly curved or straight, ribbed, rather densely scaly, glabrous, longer than the calyx, not enclosed by the calyx-lobes.

Rhododendron anthopogon D. Don var. album Davidian, var. nov.
        Aspectu R. anthopogonis D. Don sed floribus albis, foliis supra atroviridibus nitentibus recedens.
        SIKKIM. Jongri. As. white. Altitude 14,000 ft. 12/8/1913. Rohmoo Lepcha No. 937.
        TIBET, ASSAM-HIMALAYA FRONTIER TRACT. Tron. Loro Chu. An aromatic bushy shrublet with white flowers. Leaves with loose rusty red scurfy scales beneath. Scattered on the alpine slopes with No. 11804 and "Lacteum". Altitude 13,000 ft. 26. vi. 1935. Kingdon-Ward No. 11803.
        TIBET. Gautsa-Phari. A small shrub with white flowers. Altitude 13,500 ft. 19/5/1945. Bor and Kirat Ram No. 19374 (Holotype in Herb. Hort. Bot. Edin.).
        TIBET. Phari. On dry slopes, flowers white. Altitude 15,000 ft. 18/6/ 1945. Bor and Kirat Ram No. 20455.
        BHUTAN. Cheli La. nr. Ha Dzong. Rhododendron sp. Seed taken. Altitude 12,000 ft. 22.10.1949. F. Ludlow, G. Sherriff, & J. H. Hicks No. 17550.
        BHUTAN. Shingbe. Me La. Hab. growing amongst other rhododendrons by side of waterfall. Shrub 2 ft.-3 ft. (Supplementary white variety; see No. 20655). Altitude 10,500 ft. 21.9.1949. F. Ludlow, G. Sherriff, & J. H. Hicks No. 20655A.
        NEPAL. Arun Valley. Maghang Khola, E. of Num. On open hillside. Height 1 ft. Corolla white. 11,000 ft. 7.5.1956. John D. A. Stainton No. 239.
        NEPAL. Tamur Valley. Mewa Khola. Topke Gola. Amongst small shrubs. Corolla white. Height 2 ft. 12,500 ft. 14.5.1956. John D. A. Stainton No. 270.
        The variety differs from the species in that the flowers are white. It is a compact or broadly upright shrub 30-92 cm. (1-3 ft.) high. The leaves are dark green and shining on the upper surface.
        This plant was first collected by Rohmoo Lepcha in August 1913 at Jongri, Sikkim. Subsequently it was found by other collectors in Nepal, Bhutan and Tibet. It grows on dry slopes, on open hillsides, and amongst other rhododendrons and small shrubs, at elevations of 3,173-4,575 m. (10,500-15,000 ft.).
        It was introduced by Ludlow, Sherriff and Hicks under No. 17550 from Bhutan in 1949 from an elevation of 3,660 m. (12,000 ft.). In cultivation it is quite hardy, free-flowering, and is well worth a place in every collection of rhododendrons.


Volume 34, Number 4
Fall 1980

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