Tag:

Sikkim

Flowers of Sikkim — 350 species from the Sikkim Himalaya in northeast India, a compact yet botanically extraordinary region that climbs from subtropical valleys to the alpine zone beneath Kangchenjunga. Sikkim is a classic centre of Himalayan plant diversity, celebrated for its rhododendrons, primulas, orchids and gentians. Each entry provides a botanical description, distribution, habitat and flowering season with the original field photograph.

Ericaceae

Rhododendron baileyi

by GP Jürgens

Balf. f.

Sikkim2011 204
Sikkim Lachung 3100m, June
Sikkim2011 205
Sikkim Lachung 3100m, June
Sikkim2004 435 P758
Sikkim/India Lachung 3600m May

Description

Rhododendron baileyi is a lepidote shrub of the eastern Himalaya, native to Sikkim and the rest of northern India, Bhutan and south-eastern Tibet in China, with the remaining GBIF records (Great Britain, Canada, Japan, Sweden, United States) reflecting its presence in cultivation. Its roughly 121 georeferenced records indicate a narrowly distributed but well-known garden plant. It grows in open subalpine forest, rocky slopes and rhododendron-dominated thickets at roughly 3000-4300 m. The Sikkim collections noted above, from the Lachung valley at 3100-3600 m in May and June, are characteristic of its montane habitat.

It is a small to medium evergreen shrub with scaly young shoots, the leaves elliptic to oblong, leathery and densely covered beneath with overlapping reddish-brown lepidote scales that give the undersurface a rusty, almost continuous coating. The flowers are borne in compact terminal clusters and are widely campanulate to saucer-shaped, deep reddish-purple to magenta, often darker-spotted within, with the corolla and the exserted stamens and style bearing scattered scales. The fruit is a small ovoid, scaly, septicidal capsule splitting to release numerous minute seeds.

Within the genus Rhododendron, R. baileyi belongs to the lepidote subgenus and is placed in subsection Baileya, a small group distinguished by its strongly flattened, overlapping leaf scales and richly coloured flat-faced flowers. Named for the explorer F. M. Bailey, it has been valued in horticulture since its introduction. Pollination is by bumblebees and other long-tongued insects of the high Himalaya. Although not broadly assessed, its limited natural range and dependence on intact subalpine shrubland make it locally sensitive to grazing, fire and forest disturbance.

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

Ericaceae

Rhododendron campanulatum

by GP Jürgens

D. Don

Sikkim2004 128 P223
Sikkim/India Singalila 2600m April
Nepal 97 229 P476
Nepal Thudam 3800m April
Nepal 97 239 W494
Nepal Thudam 3800m April
Nepal 2001 328 ergebnis ergebnis scaled
Nepal 2001 351 ergebnis ergebnis scaled
Nepal 2001 327 ergebnis ergebnis scaled
Nepal (Gorkha) Rupina-La 3250m, May

Description

Rhododendron campanulatum D. Don is an evergreen Himalayan shrub or small tree distributed through Nepal (NP), India (IN), Bhutan (BT) and southern China (CN), with GBIF logging 1357 occurrences plus numerous cultivated records from Britain, North America and Europe. It forms dense thickets at and above the temperate treeline, in subalpine fir and birch forest and on open alpine slopes. The image documents populations across its range: Singalila on the Sikkim-India ridge at 2600 m in April, Thudam in Nepal at 3800 m in April, and the Rupina-La in Gorkha at 3250 m in May, reflecting the species' role as a dominant of the upper forest belt.

The plant is a much-branched shrub with stout twigs and a characteristically thick, rufous indumentum of dendroid hairs on the lower leaf surface. The leaves are coriaceous, elliptic to oblong, dark green and glabrous above, the undersurface densely felted with cinnamon-brown to fawn tomentum. The flowers are borne in compact terminal trusses; each has a broadly campanulate corolla, pale lilac to rose-purple or whitish, often spotted within, with five lobes and ten stamens. The fruit is a curved, woody, septicidal capsule releasing numerous small winged seeds.

Rhododendron campanulatum belongs to subgenus Hymenanthes, the large-leaved tomentose-leaved alliance, and includes subsp. aeruginosum with strikingly glaucous young foliage. As a treeline dominant it strongly influences alpine ecology, and recent studies have documented its upslope migration and densification in response to warming, with implications for fragile alpine meadows. It is widely cultivated and has contributed to garden hybrids. The species remains common and is not considered threatened.

Author: D. Don · Sources: POWO (Kew), GBIF, Flora of Nepal, Flora of Bhutan, Rhododendron monograph (Davidian; Royal Botanic Garden Edinburgh revision)

Ericaceae

Rhododendron campylocarpum

by GP Jürgens

Hook. f.

Bh2008 237 P374
Bhutan Tumching-La, 3600m April
Bh09 83 G141
Bhutan Langchlakha, 3700m June
Sikkim2004 403 G687
Sikkim/India Lachung 3300m May
Sikkim 2006 372 ergebnis
India West-Bengal, Tamrong 2850m, May

Description

Rhododendron campylocarpum is an East Himalayan species distributed through the higher ranges of Nepal, Sikkim and Darjeeling in India, Bhutan, southern Tibet (China) and northern Myanmar, with abundant horticultural records (GB, US, NZ, etc.) reflecting long cultivation in temperate gardens; GBIF holds some 676 occurrences. It grows in the upper temperate and subalpine zone, typically between about 2850 and 3700 m, as documented at Tumching-La (3600 m) and Langchlakha (3700 m) in Bhutan, at Lachung (3300 m) in Sikkim and at Tamrong (2850 m) in West Bengal, inhabiting conifer and Abies forest margins, rhododendron thickets and moist rocky slopes near the treeline. It flowers in late spring and early summer (April-June).

It is an evergreen, much-branched shrub or small tree reaching 1-4 m, with smooth, peeling bark. The leaves are alternate, clustered toward the branch tips, broadly ovate to elliptic-oblong, 4-10 cm long, rounded to cordate at the base, glabrous and dark green above and conspicuously glaucous beneath. The inflorescence is a lax, terminal truss of 5-12 flowers; the corolla is campanulate, 3-4 cm across, clear sulphur- to canary-yellow, frequently with a crimson basal blotch within. Stamens are 10, included; the ovary and slender style are usually glandular. The fruit is a curved, cylindrical capsule, the epithet ("campylocarpum", bent fruit) referring to this curvature.

The species belongs to subgenus Hymenanthes, subsection Campylocarpa, a small group of yellow-flowered Himalayan rhododendrons including R. wardii and R. callimorphum, and it hybridises freely in the wild and in cultivation. Introduced by J. D. Hooker in the 1850s, it became an important parent of many garden hybrids and is an early-summer nectar source for bumblebees and other high-altitude pollinators. Though locally common and not globally threatened, individual populations are subject to grazing, fuelwood collection and the upward shift of the treeline.

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

Ericaceae

Rhododendron campylocarpum x Rhododendron thomsonii

by GP Jürgens
Sikkim2004 404 P689
Sikkim/India Lachung 3400m May

Description

This plant is a natural hybrid between Rhododendron campylocarpum and Rhododendron thomsonii, both subalpine to alpine shrubs of the Eastern Himalaya whose ranges overlap broadly in Sikkim, Bhutan, eastern Nepal and southern Tibet. Because it is a hybrid rather than a described species, it carries no meaningful GBIF distribution of its own — the apparent global record set and the placeholder accepted name 'Plantae' reflect database artefacts, not a real occurrence pattern. Such intermediates arise wherever the two parents grow intermingled in mossy fir and Rhododendron forest and on open subalpine slopes. The photographed plant from Lachung in northern Sikkim, near 3400 m and flowering in May, lies squarely within the elevational overlap zone of about 3000-4000 m where natural hybridisation is frequent.

Morphologically the hybrid is intermediate between its parents. From R. thomsonii it tends to inherit smooth, often peeling, reddish bark, rounded to obovate-orbicular leaves glaucous beneath, and a calyx that is enlarged and cupular; from R. campylocarpum it derives a more campanulate corolla and a tendency toward yellow pigmentation. The resulting flowers are typically campanulate and pale yellow to creamy, frequently flushed or blotched pink to rose, borne in loose terminal trusses; the curved capsule shows the influence of campylocarpum (the 'curved-fruited' parent). Stamens number ten and the style is glabrous.

Both parents belong to Rhododendron subgenus Hymenanthes (the elepidote rhododendrons), and their hybrid swarms are a classic example of natural introgression, long noted in Sikkim by J. D. Hooker. These intermediates blur species limits in the field and are of horticultural importance, both parents being foundational in the breeding of yellow- and red-flowered garden hybrids.

Sources: POWO (Kew), GBIF, Flora of Bhutan, The Rhododendron Handbook (Royal Horticultural Society), Cox & Cox A Encyclopedia of Rhododendron Species, Hooker The Rhododendrons of Sikkim-Himalaya

Ericaceae

Rhododendron ciliatum

by GP Jürgens

Hook. f.

Bhutan2014 551
Bhutan Phobjika 2810, May
Bhutan2014 553
Bhutan Phobjika 2810, May
Bh2008 404 P634
Bhutan Phobjika, 3100m April
Bh2008 404 P634 scaled
Bhutan Phobjika, 3100m April
Nepal 1994 70 ergebnis
Ost-Nepal Jaljale Himal, 2800m April

Description

Rhododendron ciliatum is a low evergreen shrub of the Eastern Himalaya, with verified native occurrences in India, Nepal, Bhutan and China; numerous further GBIF records from Britain, North America, Austria, Italy, New Zealand and elsewhere reflect its wide cultivation. It grows on open hillsides, rocky slopes and forest margins, often epiphytically on mossy trunks, in the upper-temperate and subalpine zones between about 2700 and 3700 m. The cited material from Phobjika in Bhutan (2810-3100 m, April-May) and the Jaljale Himal of eastern Nepal (2800 m, April) shows the species in its characteristic early-spring flowering.

It forms a compact, rounded shrub usually under 1.5 m with peeling reddish-brown bark and bristly young shoots. The elliptic to oblong leaves are leathery and dark green, conspicuously fringed at the margins and on the midrib beneath with long stiff cilia, the feature giving the species its name, and scaly below. The flowers are borne in small terminal trusses of two to five; the corolla is broadly funnel-campanulate, white to pale pink, often deeper rose in bud, with a slightly nodding posture. The fruit is a small ovoid scaly capsule that splits to release abundant minute winged seeds.

Rhododendron ciliatum belongs to subgenus Rhododendron, subsection Maddenia, a lepidote (scaly) group, and was described by J.D. Hooker from his Sikkim collections; it has contributed extensively to horticultural hybridisation for its hardiness and early bloom. Ecologically it is an early-spring nectar source in the high forest. Widespread and locally common across its native range and abundant in cultivation, it is not regarded as threatened.

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

Ericaceae

Rhododendron cinnabarinum

by GP Jürgens

Hook. f.

Bhutan2014 877
Bhutan Chele-La 2850m, May
Bhutan2014 882
Bhutan Chele-La 2850m, May
Bh2008 221 P349
Bhutan Tumching-La, 3400m April
Bh2008 222 G350
Bhutan Tumching-La, 3400m April
Sikkim2003 191 G262
Sikkim Dzongri 3900m 08.2003

Description

Rhododendron cinnabarinum is an Eastern Himalayan species native to Bhutan, Sikkim and adjacent northeastern India, Nepal and southern Tibet (China), the nearly 768 records also reflecting its popularity in cultivation in Britain, North America and elsewhere. It is a shrub of the cool temperate to subalpine zone, the images documenting plants on the Chele-La in Bhutan at about 2850 m in May, the Tumching-La at about 3400 m in April, and Dzongri in Sikkim near 3900 m. It grows in fir and mixed forest, rhododendron thickets, forest margins and open subalpine scrub on moist, acidic, humus-rich slopes within the monsoon-influenced humid belt of the range.

It is an evergreen shrub reaching one to several metres, with smooth bark and aromatic foliage. The leaves are elliptic to obovate, conspicuously glaucous-blue when young and densely scaly (lepidote) beneath, the scales being diagnostic of the lepidote rhododendrons. The pendulous, tubular-campanulate to narrowly funnel-shaped flowers are borne in small terminal trusses and are noted for their waxy texture and remarkable colour range, from cinnabar-red and orange to plum and yellow; the ten stamens and the style are enclosed within the elongate corolla tube, which matures into a scaly capsule.

Described by J.D. Hooker, the species is placed in subgenus Rhododendron, subsection Cinnabarina, the only members of the lepidote group with markedly tubular, drooping corollas suited to pollination by birds and long-tongued insects. It is variable across its range, with several recognised subspecies and varieties differing in flower colour and foliage, and is an important parent in horticulture. Locally common in suitable habitat and widely cultivated, it is not regarded as globally threatened, though parts of its native forest are under pressure.

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

Ericaceae

Rhododendron dalhousieae

by GP Jürgens

Hook. f.

Bh09 237 P397
Bhutan Wangdi 1950m, June
Bh09 238 G399
Bhutan Wangdi 1950m, June
Nepal 97 314 P620
Nepal Honggaon 2360m May
Nepal 97 418 P807
Nepal Taskigaon 3000m May
Sikkim 2006 172 ergebnis
Sikkim 2006 175 ergebnis
India West-Bengal, Samadan 2400m, May

Description

Rhododendron dalhousieae is an epiphytic or terrestrial shrub of the eastern Himalaya, distributed across India, Nepal, Bhutan and adjacent China; its c. 149 georeferenced records track the wet temperate forest belt (records from Britain and New Zealand reflect its long history in cultivation). It grows in humid broadleaf and Rhododendron-rich forest, often perched on mossy trunks and rocks or on steep banks, chiefly between 1800 and 3000 m. The image documents populations across its range, from Wangdi in Bhutan at 1950 m to Nepal's Honggaon and Taskigaon (2360-3000 m) and Samadan in West Bengal at 2400 m, flowering from May into June in the cloud-forest zone.

It is a straggling, sparsely branched shrub 1-3 m tall, frequently epiphytic, with peeling bark and large, obovate to elliptic leaves clustered toward the branch tips, glaucous beneath and bearing scattered scales. The flowers are among the most spectacular of Himalayan rhododendrons: borne in lax trusses of two to six, each broadly funnel-campanulate, 7-12 cm long, fragrant, white often flushed with pale yellow or pink, with a long tube. The ten stamens and slender style are enclosed within the corolla, and the scaly ovary matures into an elongate capsule splitting to release numerous minute winged seeds.

Described by Hooker f. (Hook. f.) from his Sikkim explorations, R. dalhousieae belongs to Rhododendron subgenus Rhododendron, section Rhododendron (the lepidote or scaly-leaved rhododendrons), and is named for Lady Dalhousie. Its large, fragrant, pale flowers suggest pollination by moths and large bees. Long prized in horticulture, it is widespread but locally uncommon and dependent on intact humid forest; habitat loss makes some populations vulnerable, though it is not formally threatened.

Author: Hook. f. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Flora of Bhutan and Sikkim, The Genus Rhododendron monograph (Edinburgh, Ericaceae)

Ericaceae

Rhododendron falconeri

by GP Jürgens

Hook.f.

Bhutan2014 349
Bhutan Tumching-La 3000m, May
Bh2008 100 P160
Bhutan Nabding, 2600m April
Bh2008 101 P161
Bhutan Nabding, 2600m April
Sikkim2004 24 P45
Sikkim West-Bengal, Sambon 1850m April
Sikkim2004 35 G61
Sikkim West-Bengal, Sambon 1850m April
Sikkim2004 31 P53 ergebnis
Sikkim Bersay 2810m, April

Description

Rhododendron falconeri is a large-leaved arborescent rhododendron native to the eastern Himalaya, occurring in Nepal, India (Sikkim, Darjeeling), Bhutan and adjacent China; the additional countries listed in GBIF (Great Britain, Canada, Belgium, Korea and others among 316 occurrences) reflect cultivated and herbarium records from botanic gardens. It grows in cool, humid temperate forest between roughly 2400 and 3300 m, forming a conspicuous component of the upper broadleaved and rhododendron-magnolia zone. The collection localities in the image caption, spanning Tumching-La and Nabding in Bhutan and Sambon and Bersay in Sikkim and West Bengal between 1850 and 3000 m in April and May, capture its flowering on misty ridge forests during the pre-monsoon.

The species is an evergreen shrub or small tree to 12 m with rough, flaking bark and stout shoots. Its very large obovate to elliptic leaves, up to 30 cm long, are dark green and rugose above and clothed beneath with a dense rusty to fawn indumentum of branched hairs, a diagnostic feature. The flowers are borne in dense rounded trusses of fifteen to twenty-five; each corolla is fleshy, campanulate, eight- to ten-lobed, creamy white to pale yellow and marked with a deep purple basal blotch. Fruit is a stout, curved, woody dehiscent capsule releasing numerous minute winged seeds.

Placed in subgenus Hymenanthes, subsection Falconera, R. falconeri is allied to R. hodgsonii and is among the most celebrated big-leaf rhododendrons, cultivated since its introduction by Hooker. The thick leaf indumentum and large foliage are adaptations to cool, fog-laden montane conditions, and it is pollinated chiefly by birds and large insects. While locally common and not globally threatened, Himalayan populations are pressured by fuelwood cutting, forest clearance and climate-driven upslope shifts.

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

Ericaceae

Rhododendron fragariiflorum

by G & P Jürgens

Kingdon-Ward

BhutanPG2011 241
Bhutan Tsochenchen, 3800m June

Description

Rhododendron fragariiflorum (correctly orthographed as R. fragariflorum) is a dwarf, cushion-forming shrub endemic to the high eastern Himalaya and adjacent southeastern Tibet. Its distribution, documented by GBIF across China (Xizang), India (Sikkim, Arunachal Pradesh) and Bhutan, is restricted to the alpine zone, where it grows on open, peaty slopes, in moist meadows and among rocks at elevations of roughly 3,800–5,000 m. The photographed population near Tsochenchen in Bhutan at 3,800 m in June illustrates its typical habitat above the treeline, where it forms low mats in the company of alpine sedges, primulas and other prostrate rhododendrons subjected to strong insolation, frost and a brief summer growing season.

The plant is a low, much-branched, semi-prostrate shrublet seldom exceeding 10–20 cm in height, with slender, often decumbent stems clad in persistent leaf scales. The small, elliptic to obovate leaves are coriaceous, scaly (lepidote) beneath, and dark green above, frequently with revolute margins. Distinctively, the flowers are solitary or borne in pairs and are a deep purplish-crimson to magenta, often described as strawberry-coloured, hence the epithet fragariflorum. The corolla is broadly campanulate to rotate, five-lobed and lepidote on the outer surface, with ten exserted stamens; the fruit is a small, scaly, dehiscent capsule.

The species belongs to subgenus Rhododendron, section Pogonanthum-related lepidote groups, and is taxonomically notable for its unusually open, non-tubular corolla among scaly rhododendrons. As a strict high-alpine specialist with a narrow range and modest occurrence record, it is of biogeographic interest as an indicator of intact Sino-Himalayan alpine habitats. Climate-driven upward shifts of the treeline pose the principal long-term threat to such cushion communities.

Author: Kingdon-Ward · Sources: POWO (Kew), GBIF, Flora of Bhutan Vol. 2, Flora of China Vol. 14, Cullen: Revision of Rhododendron subgenus Rhododendron (Notes RBG Edinburgh)

Ericaceae

Rhododendron fulgens

by GP Jürgens

Hook. f.

Sikkim2004 145 P253
Sikkim/India Singalila 4000m April
Sikkim2004 147 G255
Sikkim/India Singalila 4000m April
Nepal 97 213 P434
Nepal Thudam 3850m April

Description

Rhododendron fulgens is an East Himalayan shrub, with GBIF's c. 170 occurrences centred on India, Nepal, Bhutan and adjacent Tibetan China (records from GB, DE, US, CA, KR being cultivated material). It is a plant of the upper subalpine and lower alpine zones, typically 3300–4500 m, forming dense thickets at the treeline and in the understorey of Abies and Betula forest on moist, peaty, north-facing slopes. The populations photographed on the Singalila ridge (Sikkim/India) at 4000 m and at Thudam in eastern Nepal at 3850 m, both flowering in April, exemplify its preference for cool, snow-influenced ridges where it blooms before the monsoon.

It forms a stout, gnarled evergreen shrub to small tree 1–4 m tall, with smooth, peeling cinnamon to reddish-brown bark. The leaves are coriaceous, broadly elliptic to obovate, glossy dark green above and clothed beneath with a thick, persistent rusty to fulvous indumentum from which the epithet derives. The inflorescence is a compact, rounded truss of 10–20 campanulate flowers; the corolla is fleshy, deep blood-red to scarlet-crimson, about 2.5–3 cm long, with darker nectar pouches at the base. Stamens are 10, the ovary glandular, and the fruit a curved, woody, dehiscent capsule.

Described by J. D. Hooker from Sikkim, R. fulgens belongs to subsection Fulgensia within subgenus Hymenanthes and is allied to R. sherriffii and R. succothii. Though locally common across its core range and not globally threatened, its restricted treeline habitat is sensitive to grazing, fuelwood collection and shifting snowlines, and it serves as an important early-season nectar source for high-altitude pollinators.

Author: Hook. f. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, The Genus Rhododendron (Royal Horticultural Society monograph)