Logo for the Journal American Rhododendron Society

Journal American Rhododendron Society

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


Volume 30, Number 4
Fall 1976

DLA Ejournal Home | QBARS Home | Table of Contents for this issue | Search JARS and other ejournals

TWO NEW RHODODENDRON SPECIES
H. H. Davidian, Edinburgh, Scotland

Rhododendron bergii Davidian, sp. nov.
        Species R. augustinii Hemsl. affinis sed corolla rubra, habitu compacto, foliis supra nitentibus recedens.
        Frutex compactus, 1.50-2.75 m. altus; ramuli moderate vel dense lepidoti, floccosi vel glabri, perulis deciduis. Folia sempervirentia; lamina coriacea, lanceolata, oblongo-lanceolata vel oblonga, 4-7.8 cm. longa, 1.63.3 cm. lata, apice acuta vel acuminata et mucronata, basi obtusa vel cuneata, supra atroviridis nitens lepidota vel elepidota glabra vel sparsim puberula, costa media puberula, infra pallide viridis, squamis inaequalibus mediocris vel magnis brunneis inter se 1-3 diametris distantibus praedita, glabra, costa media dense vel moderate pubescentia; petiolus 0.6-1.6 cm. longus, lepidotus, pubescens vel glaber, floccosus. Inflorescentia terminalis, vel terminalis et foliis summis 1-3 axillaris, umbellata 3-5-flora, bracteis persistentibus vel deciduis; rhachis 2-3 mm. longa, lepidota, glabra; pedicelli 0.7-2 cm. longi dense lepidoti, glabri. Calyx 5-lobatus vel annularis tantum, minutus 0.5-1 mm. longus, lobis rotundatis vel ovatis, extra dense lepidotis, glabris, margine ciliatis. Corolla late infundibuliformis zygomorpha, 2.7-3 cm. longa, 5-loba, rubra postice atro-rubro-maculata, extra lepidota, glabra vel tubo pubescens. Stamina 10 inaequalia longe exserta, 1. 22.5 cm. longa; filamenta basim versus pubescentia. Ovarium oblongum vel conoideum, 2-3 mm. longum, 5-loculare, dense lepidotum, glabrum; stylus gracilis rectus, corollam aequans vel ei longior, elepidotus, glaber. Capsula oblonga, 0.7-1 cm. longa, 4 mm. lata, dense lepidota, calyce persistente.

        N. W. Yunnan. Shui-lu Shan, west of Wei-Hse. Lat. 27 degrees 12' N. Long. 99 degrees 12' E. Rhod. Shrub of 5-6 ft. In fruit. In thickets and amongst scrub in side valleys on rocky slopes. Alt. 13,000 ft. Oct. 1924. George Forrest No. 25914 (Holotype in Herb. Hort. Bot. Edin. Details of the flower are taken from a cultivated plant).
        This plant was at first described as R. augustinii var. rubrum, a native of Yunnan. It is so distinct in cultivation that it merits specific rank. The name "Rubra", in binary combination, has already been used in naming several hybrids. In order to avoid confusion, the Yunnan plant must receive a new name.
        R. bergii* was discovered by Forrest in October 1924 at Shui-lu Shan, north-west Yunnan, growing in thickets and amongst scrub in side valleys on rocky slopes at an elevation of 13,000 feet.


*"Variety bergii" under R. ciliatum in The Rhododendrons Of The World page 146 by D. G. Leach, is a nomen nudum. It bears no relation to R. bergii above.


        The species is a member of the Augustinii Subseries, Triflorum Series. It is related to R. augustinii, from which it is readily distinguished by the red flowers, by the compact habit, and by the shining upper surface of the leaves. Moreover, in cultivation it flowers in March or early April, three or four weeks before R. augustinii has opened its flowers.
        The plant has long been in cultivation under Forrest No. 25914 - Type number. It is hardy, free-flowering, and is worthy of being widely grown.
        The species is named after Mr. & Mrs. Warren E. Berg, Kent, Washington, U.S.A., in recognition of their outstanding contributions to the cultivation of rhododendrons.
        A compact shrub, 1.50-2.75 m. high; branchlets moderately or rather densely scaly, sparsely hairy with long hairs or glabrous, leaf-bud scales deciduous. Leaves evergreen, lanceolate, oblong-lanceolate or oblong, lamina coriaceous, 4-7.8 cm. long, 1.6-3.3 cm. broad, apex acute or acuminate, mucronate, base obtuse or tapered; upper surface dark green, shining, scaly or not scaly, glabrous or sparsely puberulous, midrib puberulous; under surface pale green, scaly, the scales unequal, medium-sized or large, brown, 1-3 times their own diameter apart, glabrous, midrib rather densely or moderately pubescent; petiole 0.61.6 cm. long, scaly, pubescent or not pubescent, hairy with long hairs. Inflorescence terminal, or terminal and axillary in the uppermost one to three leaves, umbellate, 3-5-flowered, flower-bud scales persistent or deciduous; rhachis 2-3 mm. long, scaly, glabrous; pedicel 0.7-2 cm. long, rather densely scaly, glabrous. Calyx 5-lobed or a mere rim, minute, 0.5-1 mm. long, lobes rounded or ovate, outside densely scaly, glabrous, margin ciliate. Corolla widely funnel-shaped, zygomorphic, 2.7-3 cm. long, 5-lobed, red, with deep red spots on the upper lobes, outside scaly, glabrous or pubescent on the tube. Stamens 10, unequal, long-exerted, 1.2-2.5 cm. long; filaments pubescent towards the base. Ovary oblong or conoid, 2-3 mm. long, 5-celled, densely scaly, glabrous; style slender, straight, as long as the corolla or longer, not scaly, glabrous. Capsule oblong, 0.7-1 cm. long, 4 mm. broad, densely scaly, glabrous, calyx persistent.

R. piercei
R. piercei is illustrated on the front cover

Rhododendron piercei Davidian, sp. nov.
        Species R. beaniano Cowan affinis sed habitu compacto patente, 1.201.50 m. alto; ramulis et petiolis esetulosis, foliis infra indumento bistrato brunneo supra paulo rugulosis differt.
        Frutex compactus patens, 1.201.50 m. altus; ramuli pilis fasciatis brunneis dense tomentosi, esetulosi, eglandulosi, sub inflorescentia 6-9 mm. diametro, perulis deciduis. Folia sempervirentia; lamina coriacea, oblonga, oblongo-ovalia vel oblongoobovata, 6-11 cm. longa, 2.7-5.2 cm. lata, apice rotundata et mucronata, basi rotundata vel paulo cordulata, supra atroviridis paulo rugulosa nitens glabra, costa media sulcata dense vel moderate tomentosa, venis primariis 10-14 impressis, infra indumento brunneo bistrato continuo, costa media prominente glabra vel dense tomentosa, venis primariis elevatis vel occultis; petiolus 1-2 cm. longus, supra sulcatus, pilis fasciatis brunneis dense tomentosus, esetulosus, eglandulosus vel raro glandulosus. Inflorescentia racemoso-umbellata 6-8-flora, bracteis deciduis; rhachis 4-5 mm. longa, tomentosa eglandulosa; pedicelli 1.21.5 cm. longi, pilis fasciatis dense vel moderate tomentosi, eglandulosi. Calyx 5-lobatus, 3-6 mm. longus, kermesinus, lobis inaequalibus, oblongis, oblongo-ovalibus vel ovalibus, glabris eglandulosis. Corolla tubuloso-campanulata, 2.8-3.6 cm. longa, kermesina, camosa, basi leviter 5-saccata; lobi 5, 1-1.3 cm. longi, 1-2 cm. lati, - rotundati emarginati. Stamina 10 inaequalia, 2-3 cm. longa, corollae breviora; filamenta glabra. Gynoecium 3-3.4 cm. longum, corollam aequans vel ei longior; ovarium oblongum vel conoideum, 5 mm. longum, 6-loculare, dense tomentosum, tomento pallide brunneo, eglandulosum; stylus gracilis rectus, basi tomentosus eglandulosus. Capsula oblonga vel gracilis, 1.41.8 cm. longa, 4-5 mm. lata, curvata, pilis fasciatis pallide brunneis dense tomentosa, eglandulosa, calyce persistente.

        Tibet. Dri La, Zayul, 1933. F. Kingdon-Ward No. 11040 (Holotype in Herb. Brit. Mus.). In herb cult. R.B.G. Edin.
        This plant has long been known under the name R. beanianum var. compactum, but further investigation of specimens and plants in cultivation shows that it merits specific status. The plant must receive a new name, because at an earlier date (1932) Hutchinson had applied the name "compactum'' to a species in the Lapponicum (R. compactum).
        R. piercei is a distinctive species belonging to the Haematodes Subseries, Neriiflorum Series. It is allied to R. beanianum, from which it differs markedly in that it is a compact spreading shrub, 1.20-1.50 m. high, the branchlets and petioles are not bristly, the indumentum on the under surface of the leaves is bistrate, brown, and the upper surface of the leaves is slightly rugulose.
        The species was introduced into cultivation by Kingdon-Ward in 1933 under No. 11040. It is hardy, free flowering, and is well worth a place in every collection of rhododendrons.
        I have named this species after Mr. & Mrs. Lawrence J. Pierce, Seattle, Washington, U.S.A., as a tribute to their remarkable achievements in the cultivation of rhododendrons.
        A compact, spreading shrub, 1.201.50 m. high; branchets densely hairy with short, brown, branched hairs, not bristly, not bristly-glandular, those below the inflorescences 6-9 mm. in diameter, leaf-bud scales deciduous. Leaves evergreen, oblong, oblong-oval or oblong-obovate, lamina coriaceous, 6-11 cm. long, 2.7-5.2 cm. broad, apex rounded, mucronate, base rounded or slightly cordulate; upper surface dark green, slightly rugulose, shining, glabrous, midrib grooved, densely or moderately hairy in its entire length or in the lower one-third, eglandular, primary veins 10-14 on each side, deeply impressed; under surface covered with a thick, brown, bistrate, continuous indumentum of hairs, midrib prominent, somewhat glabrous or densely hairy, primary veins raised or concealed; petiole 1-2 cm. long, grooved above, densely hairy with short, brown, branched hairs, not bristly, not bristlyglandular or rarely sparsely bristly-glandular. Inflorescence a racemose umbel of 6-8 flowers, flower-bud scales deciduous; rhachis 4-5 mm. long, hairy, eglandular; pedicel 1.21.5 cm. long, densely or moderately hairy with branched hairs, eglandular. Calyx 5-lobed, 3-6 mm. long, crimson, lobes unequal, oblong, oblong-oval or oval, glabrous, eglandular. Corolla tubular-cam panulate, 2.8-3.6 cm. long, crimson, fleshy, 5 nectar pouches at the base; lobes 5, 1-1.3 cm. long, 1-2 cm. broad, rounded, emarginate. Stamens 10, unequal, 2-3 cm. long, shorter than the corolla; filaments glabrous. Gynoecium 3-3.4 cm. long, as long as the corolla or longer; ovary oblong or conoid, 5 mm. long, 6-celled, densely tomentose with a fawn tomenturn, eglandular; style long, slender, straight, hairy at the base, eglandular. Capsule oblong or somewhat slender, 1.4-1.8 cm. long, 4-5 mm. broad, curved, densely hairy with long, fawn, branched hairs, eglandular, calyx persistent.


Volume 30, Number 4
Fall 1976

DLA Ejournal Home | QBARS Home | Table of Contents for this issue | Search JARS and other ejournals