Species (A-F)

Rh. albrechtii Maxim.

Lax shrub 1-2,5 m high; young shoots at first rather densely setulose-glandular, later eglandular.

Leaves deciduous, in clusters of 5 at the end of branchlets, obovate or oblong-obovate; lamina 3,6-9 cm long, 1,3-4 cm broad; both surfaces rather densely strigose.

Petiole setulose-glandular.

Inflorescence 2-5 flowers, flowers opening before or with the leaves.

Corolla rotate-campanulate, 2,3-3,5 cm long, 3,5-5 cm across, red-purple, bright purplish-rose or deep rose, with olive-green spots.

Japan. 1,000-2,000 m.

Epithet: After Dr. M. Albrecht, Russian naval surgeon.

Rh. ambiguum Hemsl.

sin. Rh. chengshienianum Fang.

Shrub 0,6-5,8 m high; branchlets densely or moderately scaly.

Leaves ovate-lanceolate, lanceolate or eliptic; lamina 2,3-8 cm long, 1,2-3,2 cm broad; upper surface scaly; underside glaucous, scaly, scales large, unequal differently coloured yellowish-brown, dark brown or blackish, contiguous to their own diameter apart.

Inflorescence 2-7 flowers.

Corolla widely funnel-shaped, 2-3,4 cm long, yellow or greenish-yellow, with green spots, outside scaly.

W Sichuan. 2,300-4,500 m.

Epithet: Doubtful.

Rh. arborescens (Pursh) Torr.

Shrub 1-3 m or rarely small tree up to 6 m high; young shoots glabrous, not setulose.

Leaves deciduous, obovate, oblanceolate or oblong-lnceolate; lamina 3-8 cm long, 1,1-3 cm broad; upper surface bright green, glabrous, not strigose; underside pale green or glaucescent, glabrous.

Inflorescence 3-8 flowers, flowers opening after the leaves are developed, very fragrant.

Pedicel glandular.

Corolla tubular-funnel-shaped, 3,5-5,2 cm long, white or pink, with or without a yellow blotch.

Stamens 4,5-6 cm long, about twice as long as the corolla-tube.

Extends from New York and Pennsylvania to Georgia, Alabama, N and S Carolina, Kentucky and Tennessee. Up to and over 1,600 m.

Epithet: Becoming tree-like.

Rh. argyrophyllum Franch.

Sudrablapu rododendrs

Rh. aureum Georgi

sin. Rh. chrysanthum Pallas

Small, prostrate or semi-prostrate or compact spreading shrub, 10-60 cm high; annual growth short; leaf-bud scales persistent.

Leaves obovate, oblanceolate, oblong-elliptic or ovate; lamina 2,3-9,5 cm long, 0,8-4 cm broad; upper surface dark green or plive-green; underside glabrous, under magnification punctulate with minute hairs.

Inflorescence a candelabroid umbel of 3-8 flowers, flower-bud scales persistent.

Corolla widely funnel-shaped, 2-3 cm long, yellow, with or without purplish spots.

Extends from the Altai mountains in W Siberia to the mountains of Mongolia, Manchuria, Kamtschatka, Sahalin Island, Kurile Islands, Korea and Japan. 1,500-2,700 m.

Epithet: Golden.

Rh. x bakeri (W.P.Lemmon et Mckay) H.H.Hume

(Rh. flammeum x Rh. canescens)

Branching shrub to 3 m, ± colonial;

Leaves narrowly obovate, 3–6 cm, less than half as wide, full-grown at anthesis;

Flowers several in a short raceme, orange-red to red, 4 cm wide, the upper lobe of the cor much wider than the others and marked with a large orange spot; sep round-ovate, glandular-ciliate, scarcely 1 mm;

Cumberland Plateau region from E Kentucky. and W Virginia. to E Tennessee., N Georgia., and N Alabama.

Epithet: After Dr. W.F. Baker, Amory University, USA.

Rh. brachycarpum D.Don ex G.Don

sin. Rh. brachycarpum ssp. brachycarpum

Rounded, occasionally, lax shrub, 1,2-3 m high; branchlets often tomentose with a thin fawn tomentum.

Leaves oblong-elliptic, oblong or oblong-obovate; lamina 7-15 cm long, 2,6-7 cm broad; upper surface bright green, glabrous; underside covered with a thin, brown or fawn, continuous unistrate indumentum of radiate hairs.

Petiole glabrous.

Inflorescence a candelabroid umbel of 8-21 flowers.

Corolla widely funnel-shaped, 2,5-3 cm long, white flushed pink or creamy-white flushed pink along the middle of the petals, with green spots.

North and Central Japan, Korea. 1,700-2,300 m.

Epithet: With short fruit.

Rh. brachycarpum ssp. fauriei (Franch.) D.F.Chamb.

sin. Rh. fauriei Franch.

Rounded compact shrub 1-3 m high; branchlets with a thin, whitish tomentum, eglandular.

Leaves oblong-obovate or oblong-elliptic; lamina 6,6-10,3 cm long, 3-5 cm broad; upper surface bright green, glabrous; underside pale green, glabrous.

Inflorescence a candelabroid umbel of 12-20 flowers.

Pedicel rather densly hairy.

Calyx minute, 1 mm long.

Corolla widely funnel-shaped, 2,1-2,5 cm long, white or yellowish, flushed pink along the middle of the petals, with green spots, outside glabrous, eglandular.

N Japan, Korea. About 2,500 m.

Epithet: After Pere L.F. Faurie, French Foreign Missions, China.

Rh. brachycarpum v. tigerstedtii (Nitz.) Davidian

sin. Rh. brachycarpum ssp. brachycarpum

This variety differs from the species type in that the leaves are longer, 15-25 cm in length, and the flowers are broader, 7 cm in breadth.

Korea. 200-900 m.

Epithet: After Dr. Tigerstedt, the former owner of Mustila Arboretum in south Finland.

Rh. bureavii Franch.

sin. Rh. cruentum Levl.

Shrub or tree 1,2-7,6 m high; branchlets densely wooly with cinnamon-coloured or rusty-red wool, glandular.

Leaves oblong-lanceolate, oblong-elliptic or elliptic; lamina 5,5-14 cm long, 2,5-6 cm broad; upper surface dark green, slightly rugulose; underside covered with a thick, woolly, cinnamon-coloured or rusty-red, continuous, bistrate indumentum of hairs.

Petiole densely woolly with cinnamon-coloured or rusty-red wool, glandular.

Inflorescence in trusses of 6-15 flowers.

Pedicel densely woolly, glandular.

Calyx glandular.

Corolla campanulate, 4-5 cm long, white, white suffused with rose, or rose, with crimson spots.

NW Yunnan, SW Sichuan. 3,200-4,300 m.

Epithet: After E. Bureau (1830-1918), a French professor.

Rh. calendulaceum (Michx.) Torr.

Shrub 1-3 m or rarely up to 5 m high; young shoots pubescent and strigose, older branchlets glabrous.

Leaves deciduous, elliptic, oblong-obovate, oblanceolate or lanceolate; lamina 3,5-8 cm long, 1,3-3,5 cm broad, upper surface pubescent or strigose; underside rather densely or moderately pubescent or strigose.

Petiole densely pubescent, and strigose.

Inflorescence 5-8 flowers, flowers opening with or shortly after the leaves.

Corolla tubular-funnel-shaped, 2,5-4 cm long, yellow, yellowish-orange, orange, red or scarlet, with orange blotch, tube glandular outside, lobes glandular or eglandular.

Pennsylvania, W Virginia, N Carolina, Georgia.

Epithet: Like a Calendula.

Rh. camtschaticum Pall.

sin. Rh. chamtschaticus (Pall.) Lindl.

Shrub, low-growing or prostrate or a cushion, 10-30 cm high, and spreads by means of underground suckers; young branchlets hairy with very long hairs, glandular or eglandular.

Leaves deciduous, short-petioled or sessile, obovate or spathulate-obovate; lamina thin, chartaceous, 1,6-5 cm long, 0,8-1,8 cm broad; margin crenulate, bristly; underside bristly.

Inflorescence 1-2 flowers produced at the ends of the young leaf-like bracts.

Corolla rotate, 1,8-2,5 cm long, tube split to the base, carmine-purple, reddish-purple or pink, spotted, outside pubescent.

Stamens 10.

From Kamtschatka, the Aleutian Islands, Alaska, southward to Saghalien, the Kurile Islands and N Japan.

Epithet: From Kamtschatka.

Rh. canadense (L.) Torr.

sin. Rh. rhodora S.F.Gmelin

Shrub 0,3-1,2 m high; young shoots puberulous, later glabrous.

Leaves deciduous, scattered, oblong, elliptic or oblong-oval; lamina 2-5,5 cm long, 0,6-2,3 cm broad, upper surface pale bluish-green, strigose; underside rather densely minutely puberulous (downy).

Petiole rather densely puberulous.

Inflorescence 3-6 flowers, flowers opening before the leaves.

Corolla rotate-campanulate, 1,6-1,8 cm long, 2-lipped, rose-purple.

Stamens 10.

From Labrador, Newfoundland, Quebec to New England, central New York, NE Pennsylvania and N New Jersey.

Epithet: From Canada.

Rh. canadnese f. albiflorum Rehder

sin. Rh. canadense (L.) Torr.

Corolla white.

Epithet: With white flowers.

Rh. carolinianum Rehder

sin. Rh. minus var. minus Carolinianum group

Shrub, compact or somewhat compact, 1-2,4 m high.

Leaves ovate, elliptic, ovate-lanceolate or lanceolate; lamina 4,6-10,8 cm long, 1,8-4,6 cm broad; upper surface dark green or pale green, scaly or not scaly; underside densely scaly, scales contiguous to their own diameter apart.

Inflorescence 4-12 flowers.

Corolla widely funnel-shaped, 2-3 cm long, pink or pale rosy-purple, with or without faint spots, outside scaly; tube shorter than, or as long as, the lobes.

Eastern USA, N and S Carolina, Tennessee.

Epithet: From Carolina.

Rh. carolinianum Rehder (balts)

Karolīnas rododendrs

sin. Rh. minus var. album Rehder

Rh. catawbiense Michx.

Shrub 1-3 m or rarely 6 m high; branchlets floccose, eglandular.

Leaves oblong-oval, oval, elliptic or oblong-elliptic; lamina 6,5-15 cm long, 2,6-3 cm broad; upper surface dark green, shiny, glabrous; underside pale whitish-green, glabrous.

Inflorescence a candelabroid umbel of 8-20 flowers.

Corolla funnel-campanulate, 3,5-4,3 cm long, rose, lilac-purple, pink or white, with olive-green spots.

N Carolina, Virginia, USA. 1,200-2,000 m.

Epithet: After the Catawba river, N Carolina, USA.

Rh. caucasicum Pallas

Shrub 0,3-1 m high; branchlets with a thin tomentum; leaf-bud scales persistent.

Leaves oblong, oblong-obovate or obovate; lamina 4-14 cm long, 1,5-4,5 cm broad; upper surface dark green, glabrous; underside covered with a thin, fawn, brown or yellowish, continuous unistrate indumentum of hairs.

Inflorescence a candelabroid umbel of 3-14 flowers; flower-bud scales persistent.

Corolla widely funnel-shaped, 2,3-3,5 cm long, pale cream, white flushed lemon-yellow, white flushed pink, very pale lemon flushed pink, or pale lemon, with or without green spots.

NE Turkey, the Caucasus, and the adjacent parts of Russia. 1,800-3,000 m.

Epithet: From the Caucasus.

Rh. concinnum Hemsl.

sin. Rh. yanthinum Bur. et Franch

Shrub or small tree 1-4,5 m high; branchlets scaly.

Leaves oblong-elliptic, oblong-lanceolate, ovate or ovate-lanceolate; lamina 2,5-8,5 cm long, 1,2-3,5 cm broad; upper surface dark green; underside densely scaly, scales yellowish, pale or dark brown or yellowish-brown, one-half their own diameter apart or contiguous.

Petiole densely scaly.

Inflorescence 2-5 flowers.

Calyx 5-8 mm long, lobes pinkish or crimson.

Corolla widely funnel-shaped, 1,5-3,2 cm long, purple, deep rosy-purple, deep pinkish or white, outside moderately or rather densely scaly.

W Sichuan, W Hubei, Shaanxi. 1,600-4,150 m.

Epithet: Neat.

Rh. cumberlandense E.L.Braun

sin. Rh. bakeri (Lemon et McKay) Hume

Shrub 0,6-2 m high, or low forms 15 cm high, stoloniferous.

Leaves deciduous, obovate; lamina 3-7 cm long, 1,5-2,5 cm broad, upper surface dark green, glabrous or pubescent; underside more or less glaucous, glabrous to sparsely pubescent, eglandular.

Inflorescence 3-7 flowers, flowers opening after the leaves.

Corolla tubular-funnel-shaped, 2,5-4 cm long, 3,5-5 cm across, yellow, orange, reddish-orange or red, with orange-yellow blotch, outside densely puberulous, glandular.

From Kentucky to Georgia, Alabama and N Carolina.

Epithet: After Dr. W.F. Baker, Amory University, USA.

Rh. dauricum L.

Shrub, 1,5-2,4 m high; branchlets scaly, rather densely minutely puberulous.

Leaves deciduous, elliptic, oblong-oval or oval; lamina 1-3,4 cm long, 0,6-2 cm broad; upper surface dark green, shiny, scaly; underside densely scaly, scales overlapping or 0,5 to 1,5 times their own diameter apart.

Inflorescence terminal, or terminal and axillary in the uppermost 1 or 2 leaves, 1-2 flowers.

Corolla widely funnel-shaped, 1,3-2,3 cm long, precocious, pink, rose-purple, reddish-purple or dark purple, outside pubescent.

Russia, Manchuria, NE China, Korea, Japan.

Epithet: From Dauria, part of SE Siberia, east of Lake Baikal.

Rh. decorum Franch.

Shrub or tree 1-9 m high; branchlets glabrous, eglandular.

Leaves oblong, oblong-obovate, obovate or oblong-oval; lamina 5-16,5 cm long, 2-7 cm broad; upper surface olive-green or bright green, wax-coated, becoming glossy when rubbed or heated; underside pale glaucous green, glabrous.

Petiole often glaucous, glabrous, eglandular.

Inflorescence in trusses of 8-12 flowers.

Pedicel moderately or rather densely glandular.

Calyx densely moderately or densely glandular.

Corolla widely funnel-campanulate, 3,5-6 cm long, fragrant, white, white suffused with rose, pink or rose, lobes 6-8.

Stamens 12-16.

Style glandular throughout to the tip with white or yellowish glands.

W and SW Sichuan, SE Tibet, NW and S Yunnan, NE Upper Burma, N Vietnam, 1,800-4,500 m.

Epithet: Ornamental.

Rh. discolor Franch.

Raibais rododendrs

sin. Rh. fortunei ssp. discolor D.F.Chamb.

Mūžzaļš, 1,2-8 m augsts krūms. Dzinumi resni un kaili, parādās vēlu - vasaras vidū. Lapas ādainas, otrādi lancetiskas, iegarenas vai iegareni otrādi olveida, 10-20 cm garas un 2,4-7 cm platas, virspusē tumši zaļas, gludas, apakšpusē gaišākas. Ziedi ziedkopās pa 6-10, piltuvveida-zvanveida, 4,6-8 cm gari, balti, gaiši sārti, ar vai bez dzeltenzaļa triepuma.  Zied jūnija beigās un jūlijā. Vainags no 7 saaugušām vainaglapām.

Suga pirmoreiz aprakstīta 1900. gadā. Latvijā introducēta 1956. gadā. Savvaļā sastopams Ķīnā - Sičuaņā un Hubejas mežos 1000-2300 m augstumā.

Epitets: dažādās krāsās.

Rh. ferrugineum L.

Shrub, 0,3-1,2 m high; branchlets densely scaly, glabrous, not bristly.

Leaves oblanceolate, lanceolate or oblong; lamina 1,6-4,3 cm long, 0,6-1,6 cm broad; upper surface dark green, shiny, not scaly, not bristly; underside densely scaly, scales dark brown or reddish-brown, overlapping.

Petiole not bristly.

Inflorescence 5-16 flowers.

Calyx minute, 0,5-1 mm long.

Corolla tubular, with spreading lobes, 1,3-1,7 cm long, crimson-purple, rose-scarlet or deep rose, rarely white, outside moderately or rather densely scaly.

European Alps, the Pyrenees, Austrian Alps, W Yugoslavia.

Epithet: Rusty-coloured.

Rh. fortunei Lindl.

sin. Rh. fortunei ssp. fortunei D.F.Chamb

Shrub or tree 1,8-9 m high; branchlets glabrous.

Leaves obovate, oblong-obovate, oblong-elliptic or oblong; lamina 7-17 cm long, 2,8-8 cm broad; upper surface olive-green or dark green, matt, glabrous; underside pale glaucous green, glabrous, under magnification with minute glands and hairs.

Petiole purple, glabrous, eglandular.

Inflorescence in trusses of 6-12 flowers.

Pedicel moderately or densely glandular.

Calyx 6-7-lobed, glandular.

Corolla widely funnel-campanulate, 4-6 cm long, fragrant, pale rose, lilac or pink; lobes 7.

Stamens 14.

Ovary densely glandular.

Style glandular throughout to the tip with white or yellowish glands.

Chekiang, Kiangsi, Anhwei, Hunan, E China. 600-1,200 m.

Epithet: After Robert Fortune (1812-1880).