Lepidote rhododendron species

Rh. ambiguum Hemsl.

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. calostrotum ssp. keleticum (Balf. f. et Forrest) Cullen

sin. Rh. keleticum Balf. f. et Forrest

A very compact, rounded spreading shrub, 15-45 cm high; or a semiprostrate shrub 8-15 cm high; branchlets densely scaly, not bristly.

Leaves oblong, oblong-elliptic, lanceolate; lamina 0,7-2,1 cm long, 3-9 mm broad; upper surface dark green, shiny; underside densely scaly, scales overlapping.

Petiole scaly, not bristly.

Inflorescence 1-3 flowers.

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

Corolla widely funnel-shaped, 1,6-3 cm long, deep purplish-crimson or deep purplish-rose, with crimson spots, outside rather densely pubescent,  scaly along the middle of the lobes.

E and SE Tibet, NW Yunnan. 3,950-4,575 m.

Epithet: Charming.

Rh. camtschaticum Pall.

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. 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. 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. 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. groenlandicum (Oeder) Kron et Judd

sin. Ledum groenlandicum Oeder

Upright shrub 0,7-2 m high; branchlets rusty tomentose.

Leaves aromatic when bruised, narrowly oblong, 2-6 cm long, 0,5-1,5 cm wide, margins very revolute; upper surface dark green with a few loose hairs; underside tomentose and lepidote, with a thick indumentum, upper layer felty, ferrugineous, obscuring the scales, and a lower layer of short white hairs; densely scaly and with reddish glands.

Petiole short, 1-5 mm.

Inflorescence to 5 cm across, many flowers.

Pedicel slender, downy.

Calyx minute.

Corolla white, rotate, 4-8 mm.

Stamens 7-10.

Ovary glandular.

Style glabrous.

Greenland, Canada, Northern USA. 1,000-1,800 m.

Epithet: From Greenland.

Rh. hirsutum L.

Small shrub 0,3-1 m high; branchlets scaly, often bristly.

Leaves obovate, oblong, oblanceolate or oblong-lanceolate; lamina 0,8-2,6 cm long, 0,4-1,3 cm broad; upper surface dark green, shiny; margin crenulate, bristly; underside pale green, laxly scaly, scales 2-4 times their own diameter apart.

Petiole bristly.

Inflorescence 4-12 flowers.

Calyx 2-5 mm long, margin with long hairs.

Corolla tubular with spreading lobes, 1-2 cm long, rose-pink, scarlet or crimson, outside scaly, inside pubescent, margin of the lobes hairy.

Central European Alps, Austrian Alps, NW Yugoslavia.

Epithet: Hairy.

Rh. impeditum Balf. f. et. W.W. Smith

Small very compact, spreading or rounded shrub 10-80 m high; branchlets short, thick, densely scaly.

Leaves elliptic, oblong-oval, oblong or oblong-elliptic; lamina 0,5-1,6 cm long, 3-6 cm broad; upper surface dark green, in both the adult and young leaves, not glaucous, somewhat shiny, scaly; underside densely scaly, scales one-half their own diameter apart.

Inflorescence 1-3 flowers.

Corolla widely funnel-shaped, 0,9-1,6 cm long, pale or deep purple, intense blue-purple, bright violet, lavender or pale or deep rose-purple.

Stamens 10, long-exserted.

Mid-W and NW Yunnan, SW Sichuan. 3,650-4,900 m.

Epithet: Tangled.

Rh. kaempferi Planch.

Shrub 30 cm-3 m high; young twigs densely brown-strigose, eglandular.

Leaves evergreen or semi-evergreen, chartaceous, dimorphic; spring leaves lanceolate, elliptic or ovate, 2-5 cm long, 1-2,5 cm broad, mostly deciduous; summer leaves smaller, oblong-obovate, obovate or elliptic, mostly persistent through the winter; in both types, upper surface is glossy green, underside is paler, brown-strigose on both surfaces and on the margin.

Inflorescence 2-4 flowers.

Pedicel densely brown-strigose.

Calyx brown-strigose.

Corolla funnel-shaped, 2,6-3,8 cm long, 2,5-4,3 cm across, salmon-red, brick-red or some shade of red.

Stamens 5.

Japan. Sea-level to about 1,600 m.

Epithet: After E. Kaempfer (1651-1716), who wrote about Japanese plants.

Rh. kiusianum Makino

Shrub, low dense much-branched, often prostrate, sometimes broadly upright,  0,3-1 m high; young shoots densely brown-strigose.

Leaves evergreen or semi-evergreen, chartaceous, dimorphic; spring leaves broadly, ovate or obovate, small, 0,8-2 cm long, 0,5-1 cm broad; summer leaves smaller, obovate, oblanceolate, elliptic or ovate, the uppermost ones are persistent through the winter; in both types upper surface is glossy, dark green, underside paler, brown-strigose on both surfaces and on the margin.

Inflorescence 2-3 flowers.

Corolla funnel-shaped, small, 1,5-2 cm long, 1,3-2,5 cm across, rose-purple, purple, red or pink, sometimes white.

Stamens 5.

Japan. 600-1,600 m.

Epithet: From Kyusu, Japan.

Rh. kotschyi Simonkai

sin. Rh. myrtifolium Schott et Kotschy

Small shrub 30-45 cm high; branchlets scaly, not bristly.

Leaves oblong, oblong-obovate or oblanceolate; lamina 0,9-2,3 cm, long, 5-8 mm broad; upper surface dark green, shiny, not scaly; margin crenulate; underside densely scaly, scales contiguous or slightly overlapping or one-half their own diameter apart.

Petiole scaly, not bristly.

Inflorescence 3-7 flowers.

Pedicel scaly, rather densely or moderately minutely puberulous.

Corolla tubular, tube slender, with spreading lobes, crimson-purple, scarlet-purple, rosy-purple or rarely white, rather densely pubescent on the tube, moderately pubescent on the lobes.

Transylvanian and Carpathian mountains and the mountains of Bulgaria and Yugoslav Macedonia. 1,500-2,400 m.

Epithet: With myrtle-like foliage.

Rh. ledebourii Pojark.

Altai Mountains, Russia.

Rh. ledebourii v. album

Rh. ledebourii v. roseum

Rh. micranthum Turcz.

Shrub 0,6-2,5 m high; branchlets thin, scaly, rather densely minutely puberulous.

Leaves oblanceolate or lanceolate; lamina 1,5-3,8 cm long, 0,4-1,5 cm broad; upper surface dark green, shiny; underside densely scaly, scales overlapping or contiguous or 5 times their own diameter apart.

Petiole scaly, minutely puberulous.

Inflorescence racemose, 10-28 flowers, rhachis 1-2,6 cm long.

Corolla campanulate, small, 4-6 mm long, white, outside scaly.

N and central China, Manchuria, Korea. 1,600-3,000 m.

Epithet: Small flowers.

Rh. minus var. minus Carolinianum group

sin. Rh. carolinianum Rehder

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. mucronulatum var. mucronulatum Turcz.

Shrub 1-4 m high; branchlets slender, scaly.

Leaves deciduous, elliptic, elliptic-lanceolate or lanceolate; lamina thin, 3,2-8 cm long, 1,3-3,6 cm broad; upper surface bright green, scaly; margin crenulate; underside pale green, scaly, scales 2-4 times their own diameter apart.

Petiole scaly, not bristly or sometimes bristly.

Inflorescence terminal, or terminal and axillary, 1-3 flowers.

Corolla widely funnel-shaped, 2,3-2,8 mm long, precocious (flowers appearing before the leaves), rose, rose-purple or reddish-purple, outside not scaly, pubescent.

SE Siberia, Manchuria, N China, Korea, Japan.

Epithet: With a small point.

Rh. x 'Obtusum'

sin. Rh. kiusianum x Rh. kaempferi 

Low shrub up to 1 m high, rarely more, sometimes nearly prostrate, twiggy; branchlets densely brown-strigose.

Leaves partly evergreen, dimorphic; spring leaves (which are formed immediately after the flowers open) are deciduous, chartaceous, lanceolate, elliptic-lanceolate to ovate, bright green above, pale beneath, both surfaces strigose; summer leaves evergreen, fairly coriaceous, smaller, obovate or oblong-obovate, both surfaces strigose.

Inflorescence 1-3 flowers.

Pedicel densely strigose.

Calyx 1-3 mm long.

Corolla funnel-shaped, 2,4-2,8 cm long, bright red, scarlet, crimson, salmon or salmon-red.

Japan.

Epithet: Blunt.

Rh. rubiginosum Franch.

Shrub or tree 0,6-9 m high; branchlets scaly.

Leaves ovate-lanceolate, elliptic-lanceolate, lanceolate or oblong-lanceolate, not aromatic; lamina 3-9 cm long, 1,3-4,2 cm broad; upper surface pale green or dark green, somewhat matt, scaly or not scaly; underside densely scaly, scales rust-coloured or brown, overlapping or contiguous, with or without widely scattered larger darker scales.

Inflorescence 4-8 flowers.

Corolla tubular-funnel-shaped, or funnel-shaped 1,6-3,1 cm long, pink, pale rose, pinkish-purple, lavender-purple or white, with crimson spots, outside scaly.

W and NW Yunnan, SE Tibet, SW Sichuan. 2,450-4,250 m.

Epithet: Reddish-brown.

Rh. russatum Balf. f. et Forrest

Shrub 0,35-1,5 m high; branchlets densely scaly.

Leaves oblong-elliptic, oblong-oval, oval, oblong or oblong-lanceolate; lamina 0,8-6,5 cm long, 0,4-2,3 cm broad; upper surface dark or pale green, densely scaly, scales nearly contiguous or overlapping; underside densely scaly, the scales large, dark brown and yellow, or unicolorous, cinnamon-red, dark brown or brown, overlapping or one-half their own diameter apart.

Inflorescence 3-10 or rarely 14 flowers.

Calyx 3-6 mm long.

Corolla widely funnel-shaped, 1,3-2 cm long, white, deep purple-blue, rose-purple, deep violet-purple, light purple or violet, outside not scaly.

NW and mid-W Yunnan, NE Upper Burma, SW Sichuan. 3,350-4,300 m.

Epithet: Reddened.

Rh. sichotense Pojark.

Rh. tomentosum ssp. tomentosum

sin. Ledum palustre L.

Dwarf shrub of thin habit, 0,3-1,2 m high; branchlets rusty tomentose, glandular.

Leaves 1-5 cm long, 0,2-0,8 cm wide, linear, margin strongly revolute; upper surface matt dark green; underside with a bistrate indumentum, upper layer thick woolly, ferrugineous, lower layer of short setulose hairs and/or reddish glands, always scaly.

Inflorescence many flowers.

Calyx minute.

Corolla 1,2 cm across white, rotate.

Stamens 7-10.

Ovary glandular.

Style glabrous.

N & Central Europe, Russia (to S Siberia). 0-2,000 m.

Epithet: Tomentose.

Rh. yedoense var. poukhanense (H. Lev.) Nakai

Shrub 0,6-1,8 m high, sometimes low or prostrate; shoots densely brown or grey-strigose, eglandular.

Leaves dimorphic, deciduous or semi-deciduous; spring leaves chartaceous, oblanceolate, lanceolate, oblong-lanceolate or ovate-lanceolate; lamina 2,8-7,8 cm long, 0,5-2 cm broad; upper surface dark green, grey or brown strigose, margin strigose, underside paler, grey or brown-strigose; summer leaves thicker, oblanceolate or lanceolate, smaller, 0,4-1 cm long; upper surface soon glabrescent, otherwise same as spring leaves.

Petiole densely brown-strigose.

Inflorescence 2-4 flowers, flowers expanding with or shortly before the leaves.

Pedicel brown-strigose.

Calyx outside brown-strigose.

Corolla widely funnel-shaped, large, 3,2-4,2 cm long, 3,2-5 cm across, rose, rosy-purple or pale lilac-purple, with purple-brown spots, fragrant.

Korea, and Tsushima (Japan). Sea-level up to 1,800 m.

Epithet: From Mt Poukhan-san, Korea.