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Spring

Ericaceae

Rhododendron grande

by GP Jürgens

Wight

Nepal1992 196 P285 ergebnis
Nepal Suketar 2400m March 
Nepal1992 197 P286 ergebnis
Nepal Suketar 2400m March 

Description

Rhododendron grande is a tree species of the eastern Himalayan temperate forest belt, ranging through Nepal, Sikkim and Darjeeling in India, Bhutan, northern Myanmar and southwestern China (Yunnan, Tibet), with cultivated and naturalised records extending to Great Britain, Belgium, Canada and the United States; the GBIF dataset comprises some 284 georeferenced occurrences. It typically grows between 2000 and 3000 m in cool, humid broad-leaved and conifer forests, ravine margins and on shaded slopes, often forming an understorey component beneath Tsuga and Quercus. The photographed plant from Suketar in eastern Nepal at 2400 m, flowering in March, is characteristic of these mid-montane mist forests where high rainfall and persistent cloud cover prevail.

It is an evergreen shrub or small tree reaching 10–15 m, with stout branchlets and smooth grey-brown bark. The leaves are large, coriaceous, oblong-elliptic to oblanceolate, 15–30 cm long, dark glossy green above and conspicuously silvery to fawn lanate-tomentose beneath with a thin plastered indumentum. The inflorescence is a dense compact truss of 15–25 flowers; the corolla is campanulate, 4–5 cm long, ivory-white to creamy with a basal crimson-purple blotch, eight-lobed, and subtended by a swollen nectary. Stamens are 16, the ovary tomentose, and the fruit a woody curved capsule dehiscing to release numerous minute winged seeds.

Rhododendron grande belongs to subgenus Hymenanthes, subsection Grandia, a group of large-leaved species centred on the Sino-Himalaya and noted for their bicoloured indumentum. As one of the earliest-flowering large rhododendrons it is valued in horticulture and draws nectar-feeding birds and bumblebees. Though not globally threatened, populations face pressure from forest clearance and grazing.

Author: Wight · Sources: POWO (Kew), GBIF, Flora of China Vol. 14, Flora of Bhutan Vol. 2, Flora of Nepal, The Genus Rhododendron (Cox & Cox)

Ericaceae

Rhododendron griffithianum

by GP Jürgens

Wight

Bhutan2014 458
Yatong-La 3200m, May
Bh2008 150 P248
Yatong-La 3200m, May
Bh2008 151 P249
Yatong-La 3200m, May
Nepal 1994 254 ergebnis
Ost-Nepal Milka-Danda 2800m May 

Description

Rhododendron griffithianum is an eastern Himalayan species centred on India (Sikkim, Arunachal), Bhutan, Nepal and adjacent China, with about 219 georeferenced records; further occurrences in Britain, the Netherlands, Canada, the United States and New Zealand reflect its long cultivation as a horticultural ornamental and parent of hybrids. It grows in cool, humid temperate forest, on shaded ridges and ravine sides, often as an understorey or forest-margin shrub between roughly 2500 and 3300 m. The photographed plants from Yatong-La at 3200 m and the East Nepal Milke Danda at 2800 m, flowering in May, typify this moist mid-montane belt.

It is a large evergreen shrub to small tree with smooth, peeling, reddish-brown bark. The leaves are elliptic-oblong, leathery, glabrous and somewhat glaucous beneath, with a rounded base and prominent midrib. The inflorescence is a lax truss of few large flowers; the corolla is broadly campanulate, white sometimes flushed pink, faintly fragrant, and among the largest of any Himalayan rhododendron, with a calyx that is unusually well developed and lobed. The fruit is an elongate, ribbed, dehiscent capsule releasing numerous minute winged seeds.

Classified in subgenus Hymenanthes, R. griffithianum has been horticulturally pivotal, contributing its size and corolla form to many hardy garden hybrids. In the wild it occupies a narrow, oceanic-monsoon climatic band, and its dependence on undisturbed humid forest renders it sensitive to logging, grazing and warming, of biogeographic interest as an indicator of the wet eastern Himalayan forest flora.

Author: Wight · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, The Genus Rhododendron (Royal Botanic Garden Edinburgh)

Ericaceae

Rhododendron hodgsonii

by GP Jürgens

Hook. f.

Bhutan2014 502
Bhutan Yatong-La 3250m, May
Bhutan2014 508
Bhutan Yatong-La 3250m, May
Bh2008 129 G216
Bhutan Pele-La, 3000m April
Bh2008 594 G889
Bhutan Chele-La 3900m April
Nepal 1994 209 ergebnis
Ost-Nepal Mewa-Khola 2500m April 

Description

Rhododendron hodgsonii is a large evergreen shrub or small tree of the temperate and subalpine zones of the eastern Himalaya, native to India (Sikkim, Arunachal), Nepal, Bhutan and adjacent China, with over 440 georeferenced records (many of the further-flung being cultivated specimens in botanic gardens). It forms a conspicuous component of the upper broad-leaved and conifer-Rhododendron forests, typically between about 2500 and 3700 m. The photographed plants span this range in Bhutan, from Pele-La and Chele-La to Yatong-La at 3000-3900 m, and in eastern Nepal at Mewa-Khola at 2500 m, flowering from April into May as the snow recedes from the high passes.

The species is distinguished by its smooth, fawn to plum-coloured peeling bark and very large, leathery, obovate-elliptic leaves up to 30 cm long, dark glossy green above and clothed beneath with a thin, silvery to fawn, plastered indumentum. The flowers are borne in dense, rounded terminal trusses of fifteen to twenty-five blooms; the corolla is fleshy, campanulate and eight- to ten-lobed, ranging from magenta-rose to pale pink with darker nectar pouches at the base. The stamens are numerous and the stout style ends in a broad capitate stigma. The fruit is a stout, curved, woody capsule.

Rhododendron hodgsonii belongs to subgenus Hymenanthes, subsection Falconera, allied to R. falconeri but separable by its thinner leaf indumentum and rich magenta corolla. Named for Brian Houghton Hodgson, it is a keystone of the Himalayan Rhododendron forests, its leaves traditionally used for wrapping and its thickets providing shelter for montane wildlife. Locally abundant and not threatened, it is widely grown in temperate gardens.

Author: Hook. f. · Sources: POWO (Kew), GBIF, Flora of Bhutan, The Genus Rhododendron (Royal Botanic Garden Edinburgh), Rhododendrons of Sikkim-Himalaya (Hooker)

Ericaceae

Rhododendron kendrickii

by GP Jürgens

Nutt.

Bhutan2014 334
Bhutan Tumching-La 2900m, May
Bhutan2014 359
Bhutan Tumching-La 2900m, May

Description

Rhododendron kendrickii is an eastern Himalayan species centred on Bhutan, north-east India (Arunachal Pradesh) and adjacent south-west China and northern Myanmar, with Nepal at the western limit; the 71 georeferenced records also include cultivated material in New Zealand. It is a component of cool, humid temperate forest, growing in mixed evergreen woodland, on forest margins and steep mossy slopes. The Bhutan collection at Tumching-La at about 2900 m sits squarely within its typical altitudinal range of roughly 2400-3300 m in the upper temperate broadleaved zone, where it flowers in spring.

It is an evergreen shrub or small tree, often 3-6 m tall, with smooth bark and stout branchlets. The leaves are oblong-lanceolate to narrowly elliptic, leathery, acuminate, dark glossy green above and pale beneath, with a prominent midrib and narrowly recurved margins. The flowers are borne in compact, many-flowered trusses; the corolla is tubular-campanulate, fleshy, and rich crimson to scarlet with darker nectar pouches at the base. Stamens are typically ten, the style glabrous, and the ovary develops into a woody, curved capsule.

The species belongs to subgenus Hymenanthes, the elepidote (non-scaly) rhododendrons, within subsection Irrorata, characterised by tubular red corollas and glabrous ovaries. The brightly coloured, nectar-rich flowers are adapted to bird and insect pollination in the spring monsoon margin. Locally common within its range and not currently regarded as threatened, it nonetheless depends on intact temperate forest and is affected by logging, grazing and fire.

Author: Nutt. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Cox & Cox The Encyclopedia of Rhododendron Species, The Rhododendron Handbook (Royal Horticultural Society)

Ericaceae

Rhododendron kesangiae

by GP Jürgens

D.G.Long & Rushforth

Bhutan2014 426
Bhutan Yatong-La 2900m, May
Bhutan2014 431
Bhutan Yatong-La 2900m, May
Bh2008 104 P168
Bhutan Nobding, 2700m April
Bh2008 370 P573
Bhutan Nobding, 2700m April
Bh2008 227 P359
Bhutan Nobding, 2700m April
Bh09 280 G462
Bhutan Pele-La, 3000m June

Description

Rhododendron kesangiae is a large-leaved rhododendron effectively endemic to Bhutan, where it is a conspicuous component of the temperate forest belt; GBIF records around 169 occurrences, the points from Canada, Sweden and Great Britain reflecting plants grown in specialist gardens and arboreta. It forms forests and thickets on cool, humid mountain slopes, typically between about 2700 and 3500 m, often in association with other big-leaved rhododendrons, magnolias and conifers. The illustrated collections from Yatong-La (2900 m, May), Nobding (2700 m, April) and Pele-La (3000 m, June) span its core range in central and western Bhutan and its spring-to-early-summer flowering.

It is a small tree or large shrub with stout branches and a rough, flaking bark. The large, elliptic to obovate leaves are leathery, dark green and somewhat rugose above, with the lower surface covered in a thin, silvery to pale fawn indumentum. The flowers are borne in dense, dome-shaped terminal trusses; the corolla is broadly campanulate, pale to deep pink or rose-purple, usually marked with a darker basal blotch, and contains numerous stamens around a stout ovary. The fruit is a woody, curved, dehiscent capsule releasing many small seeds.

Described only in 1991 by D.G. Long and Rushforth and named for Queen Kesang of Bhutan, R. kesangiae belongs to subsection Grandia (the large-leaved Himalayan rhododendrons), distinguished by leaf size, indumentum and flower colour. Its narrow, essentially Bhutanese distribution makes it a notable endemic of conservation interest, dependent on the continued integrity of mid-montane forest.

Author: D.G.Long & Rushforth · Sources: POWO (Kew), GBIF, Flora of Bhutan, The Genus Rhododendron (Cullen & Chamberlain), Rhododendrons of Bhutan

Ericaceae

Rhododendron keysii

by G & P Jürgens

Nutt.

Bhutan2014 529
Bhutan Pele-La 2900m, May
Bhutan2014 643
Bhutan Pele-La 2900m, May
BhutanPG2011 262011 Bhutan Rhod. keysii scaled
Bhutan Pele-La, 2800m June

Description

Rhododendron keysii is an eastern Himalayan shrub native to Bhutan, India (Arunachal Pradesh, Sikkim) and southern Tibet (China), with 202 georeferenced occurrences; further records from Canada, Great Britain and New Zealand reflect its cultivation as a curiosity in temperate gardens rather than a natural range. It grows in cool, humid montane and temperate forest, in scrub, forest margins and as an epiphyte or terrestrial shrub among conifers and broad-leaved trees, generally between about 2400 and 3300 m. It was photographed at the Pele-La pass in Bhutan at 2800 to 2900 m in May and June, within the moist mid-montane belt where mist and high rainfall favour its growth.

It is an erect, sparsely branched evergreen shrub 1 to 3 m tall, with scaly young shoots and rather thin, elliptic-lanceolate leaves that are lepidote beneath. The flowers are highly distinctive among rhododendrons: borne in small axillary clusters along the upper stems, they are narrowly tubular to cylindrical, only slightly flared at the mouth, and bicoloured, with an orange-red to brick-red tube and contrasting yellow-green lobes. The corolla shape recalls a Correa or a small Cestrum rather than a typical rhododendron. The fruit is a slender scaly capsule.

The species belongs to Rhododendron subgenus Rhododendron, section Rhododendron (subsection Cinnabarina, the keysii alliance), and its tubular axillary flowers make it instantly recognisable. The narrow tube and exserted style point to pollination by sunbirds. Ecologically it is a component of mossy montane forest undergrowth. It is not regarded as threatened, though uncommon and locally distributed, and is valued horticulturally for its unusual floral form.

Author: Nutt. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, The Genus Rhododendron (Cullen & Chamberlain monograph)

Ericaceae

Rhododendron lanatum

by GP Jürgens

Hook. f.

Bhutan2014 374
Bhutan Tumcheng-La 3900m, May
Bhutan2014 375
Bhutan Tumcheng-La 3900m, May
Bh2008 252 P398
Bhutan Tumching-La, 3400m April
Bh2008 270 P424 scaled
Bhutan Tumching-La, 3700m April
Bh2008 271 P425 1
Bhutan Tumching-La, 3700m April

Description

Rhododendron lanatum is an East Himalayan species restricted to the eastern Himalaya, ranging from Sikkim and adjacent northern India through Bhutan to south-eastern Xizang and Yunnan in China, with peripheral records in Nepal; its roughly 180 georeferenced occurrences (IN, BT, CN, NP) reflect a comparatively narrow distribution, supplemented by garden records in Britain and Sweden. It is a component of the subalpine Rhododendron-Abies forest and shrubberies, growing on humus-rich, acidic slopes and rocky moraine between about 3000 and 4300 m. The plants documented on the Bhutanese passes of Tumching-La and Tumcheng-La between 3400 and 3900 m, flowering from April into May, occupy exactly this cool, cloud-soaked subalpine zone.

It is an evergreen shrub or small tree to 3-4 m, conspicuous for the dense rusty to fawn woolly (lanate) indumentum that clothes the young shoots, leaf undersides and bud scales. The leaves are coriaceous, oblong-elliptic, glabrous and dark green above but covered beneath with a thick, two-layered tomentum of branched hairs. The bell-shaped (campanulate) flowers, pale to sulphur-yellow and often flecked with crimson at the base, are 3-4 cm long and grouped in dense terminal trusses of up to a dozen; the corolla bears five lobes, ten stamens and a glabrous ovary. The fruit is a curved, woody, septicidal capsule releasing numerous minute winged seeds.

Rhododendron lanatum belongs to subsection Lanata of subgenus Hymenanthes, a small group defined by their woolly indumentum and yellow campanulate flowers, allied to R. wightii. Its narrow eastern Himalayan range and dependence on intact subalpine forest make it locally vulnerable to grazing, fire and woodland degradation, though it remains frequent within Bhutan's protected highlands.

Author: Hook. f. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Cox's The Larger Rhododendron Species, The Genus Rhododendron (Royal Botanic Garden Edinburgh)

Ericaceae

Rhododendron leptocarpum

by GP Jürgens

Nutt.

Sikkim2004 436 P760
Sikkim/India Lachung 3600m May
Sikkim2004 437 P761
Sikkim/India Lachung 3600m May

Description

Rhododendron leptocarpum is an Eastern Himalayan endemic restricted to the moist temperate and subalpine belt of Sikkim, Bhutan, adjacent India, southern Tibet (China) and northern Myanmar, where GBIF documents some 119 georeferenced collections across the four countries CN, IN, MM and BT. It is an epiphytic or terrestrial shrub of mossy fir and Rhododendron forest, frequently perching on trunks, boulders and humus-laden ledges in a cool, perhumid, fog-bathed climate. The photographed plant at Lachung in northern Sikkim, growing near 3600 m and flowering in May, is typical of its altitudinal range of roughly 2700-4000 m.

The species is a small, twiggy shrub, often pendulous or scandent when epiphytic, with thin, flaky bark and slender, scaly young shoots. The leaves are evergreen, coriaceous, elliptic to oblong-lanceolate, glossy above and densely lepidote beneath, the scales golden to ferruginous. The campanulate to broadly funnelform corolla is comparatively small, pale to deep yellow, sometimes flushed greenish, borne in few-flowered terminal umbels; the stamens are 10 and the slender style is sharply deflexed. The diagnostic fruit is an elongate, narrowly cylindrical, curved capsule, the slenderness of which gives the epithet leptocarpum ('slender-fruited').

Placed in Rhododendron subgenus Rhododendron, the lepidote (scaly-leaved) rhododendrons, R. leptocarpum belongs to a group of small-flowered yellow species centred on the wettest Eastern Himalayan ranges. Its epiphytic habit and narrow elevational and geographic span make it a sensitive indicator of intact, high-humidity cloud forest, a habitat increasingly fragmented by grazing, fuelwood collection and warming-driven upslope shifts of the forest belt.

Author: Nutt. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, The Rhododendron Handbook (Royal Horticultural Society), Cox & Cox A Encyclopedia of Rhododendron Species

Ericaceae

Rhododendron lindleyi

by GP Jürgens

T. Moore

Bhutan2014 311
Bhutan Jakar 2400m, May
Bhutan2014 448
Bhutan Jakar 2400m, May
Sikkim2004 56 G98
Sikkim West-Bengal, Bersay 2810m April
Nepal 1994 257 ergebnis
Ost-Nepal Milka-Danda 2850m April 
Nepal 1994 263 ergebnis
Ost-Nepal Milka-Danda 2850m May 

Description

Rhododendron lindleyi is an epiphytic to terrestrial rhododendron of the eastern Himalaya, recorded in GBIF from India, Nepal, Bhutan, China and Myanmar across 154 occurrences. It is characteristic of cool, humid mid-montane broad-leaved and conifer forest, growing as an epiphyte on mossy trunks or on cliffs and steep banks between roughly 2200 and 3000 m. Collections cited from the image span Jakar in Bhutan at 2400 m in May, Bersay in the Sikkim-West Bengal borderlands at 2810 m in April, and Milka-Danda in east Nepal at 2850 m in April-May, indicating a spring-flowering species of the perhumid forest belt.

It is a straggling, sparsely branched shrub 1-3 m tall with smooth, peeling reddish-brown bark and rather thin, scaly branchlets. The leaves are elliptic-oblong, leathery, glaucous and densely lepidote (scaly) beneath. The inflorescence is a loose terminal truss of 3-6 large, fragrant flowers; the corolla is broadly funnel-campanulate, 7-10 cm long, white often flushed with pink and marked with a yellow basal blotch, the tube exterior bearing scattered scales. There are usually ten stamens, an elongate scaly style, and the fruit is a slender, scaly, septicidal capsule releasing numerous minute winged seeds adapted to epiphytic establishment.

The species belongs to Rhododendron subgenus Rhododendron section Maddenia, the lepidote, often epiphytic, large-flowered rhododendrons. Named for the botanist John Lindley, it is prized in horticulture for its scented bloom. Pollination is by long-tongued insects, with dust-seed dispersal favouring colonisation of bark and rock. Though locally frequent, its dependence on undisturbed humid forest leaves it sensitive to habitat clearance.

Author: T. Moore · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, The Genus Rhododendron (Edinburgh Revision)

Ericaceae

Rhododendron neriiflorum var. appropinquans

by GP Jürgens

(Tagg & Forrest) W.K. Hu

Bh2008 268 P421
Bhutan Ura 3400m, April
Bhutan2014 540
Bhutan Pele-La 3000m, May

Description

Rhododendron neriiflorum var. appropinquans is an evergreen shrub of the eastern Himalaya, known from a small number of records: GBIF documents only about 9 occurrences, confined to China (Yunnan/Tibet) and Bhutan. It grows in the temperate and subalpine forest belt, on rhododendron-clad slopes, forest margins and rocky banks broadly between 3000 and 3600 m. The photographed plants are from Bhutan at Ura (3400 m, April) and the Pele-La (3000 m, May), flowering in spring as the snow recedes, when the bright corollas appear against cool, humid, peaty mountain soils.

The plant is a much-branched shrub with leathery, evergreen leaves that are elliptic to oblong, dark green and glabrous above and glaucous to whitish-papillose beneath, recalling the foliage of an oleander as the specific epithet neriiflorum implies. The flowers are borne in a compact terminal truss of several blooms; the corolla is tubular-campanulate, fleshy in texture and a vivid crimson to scarlet, with conspicuous dark nectar pouches at the base. Stamens and the long style are exserted, and the calyx is fleshy and often coloured. The fruit is a curved, cylindrical capsule that dehisces septicidally to release numerous minute seeds.

Rhododendron neriiflorum belongs to subgenus Hymenanthes, subsection Neriiflora, a Sino-Himalayan complex of red-flowered species in which infraspecific variants such as var. appropinquans are distinguished by leaf indumentum and floral detail. GBIF treats the name as accepted. Its very restricted documented range and narrow ecological niche make it of biogeographic interest and potentially of conservation concern amid habitat change in eastern Himalayan rhododendron forests.

Author: (Tagg & Forrest) W.K. Hu · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Royal Horticultural Society revision of Rhododendron