Tag:

Bhutan

Flowers of Bhutan — 1326 plant species documented across the Bhutanese Himalaya, from dense broadleaf and conifer forests to alpine scrub and meadows. Bhutan’s largely intact wilderness shelters an exceptional diversity of orchids, rhododendrons, primulas and Himalayan poppies, many of them regional endemics. Each species page includes a botanical description, distribution, habitat and flowering time, with the original photograph and its recorded altitude and locality.

Malvaceae

Abelmoschus manihot

by GP Jürgens

(L.) Medik.

Bhutan2012 1060
Bhutan Anthso 950m, October

Description

Abelmoschus manihot is a tall, robust herb of warm-temperate and subtropical Asia, now pantropically distributed through long cultivation. GBIF records span China, India, Nepal, Japan, Korea and much of Southeast Asia, together with Australia, Pacific islands and the Americas, reflecting both its native Asian range and widespread introduction. In the Himalaya it occupies forest margins, scrub, roadsides, terrace banks and disturbed ground in the foothills and lower montane zone, generally below about 1600 m. The photographed plant grows at Anthso in Bhutan at around 950 m, flowering in October. With more than 3200 occurrences it is among the better-documented Asian mallows.

It is an erect, hispid annual or short-lived perennial reaching 1 to 2 m, the stems bristly with stiff hairs. The leaves are large, long-petiolate, palmately 3- to 7-lobed or sometimes nearly entire, the lobes coarsely toothed, and bear conspicuous narrow segments in the epicalyx. The flowers are large and showy, solitary in the upper leaf axils; the epicalyx comprises several narrow bractlets and the spathaceous calyx splits down one side and falls with the corolla. The five broadly obovate petals are pale to deep yellow with a dark purple-maroon centre. The numerous stamens are united into a staminal column typical of Malvaceae. The fruit is an oblong, hispid loculicidal capsule containing many reniform seeds.

Long cultivated, the species is valued as a leafy vegetable, for its mucilaginous tissues used in papermaking and as a sizing agent, and in traditional medicine; ornamental and food forms exist. Its wide tolerance of disturbance and human dispersal make it abundant, and it is of least conservation concern across its range.

Author: (L.) Medik. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Borssum Waalkes Malesian Malvaceae revision

Pinaceae

Abies densa

by GP Jürgens

Griff.

Bhutan2015 402
Bhutan Tumching-La 4000m, October
Bhutan2014 420 ergebnis
Bhutan Jakar 2400m, May
Sikkim 2006 82 ergebnis
Sikkim, West-Bengal Kalipokhri 3100m, May

Description

Abies densa, the Bhutan or eastern Himalayan fir, is a large evergreen conifer of the eastern Himalaya, ranging through Bhutan, Sikkim and adjacent India, eastern Nepal, southern China and northern Myanmar (gbif_countries: BT, IN, CN, NP, MM, CA, ZZ, BE), with about 192 GBIF occurrences. It is the dominant tree of the upper subalpine forest belt, forming dense stands often mixed with Rhododendron, birch and juniper and grading into the treeline krummholz. The illustrated records span Jakar in Bhutan at about 2400 m up to Tumching-La near 4000 m and Kalipokhri in the Sikkim–West Bengal borderland at about 3100 m, documenting its occupation of the cool, humid, high-montane to subalpine zone.

The tree reaches considerable height with a straight bole and conical crown, bearing horizontally spreading branches. The needle-like leaves are arranged spirally but pectinately spread, linear and flattened, dark green and glossy above with two whitish stomatal bands beneath, and notched or rounded at the apex. The pollen cones are small and lateral; the seed cones are erect, cylindrical, dark violet to blue-black when young, and, as in all firs, disintegrate on the tree at maturity to release winged seeds, leaving the persistent central axis standing.

Closely allied to Abies spectabilis of the western Himalaya, A. densa is sometimes treated as its eastern vicariant, the two replacing one another along the range. It is an ecologically important timber and watershed species and a keystone of subalpine forest. Though still locally abundant, its treeline populations are sensitive to climate shifts and grazing, and it is assessed as of Least Concern overall while warranting monitoring at range margins.

Author: Griff. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Farjon's A Handbook of the World's Conifers, IUCN Red List conifer assessments

Sapindaceae

Acer cappadocicum

by GP Jürgens

Gled.

Bhutan2014 823
Bhutan Mo-Chu 1600m, May
Bhutan2014 824
Bhutan Mo-Chu 1600m, May

Description

Acer cappadocicum is a deciduous maple with a remarkable disjunct distribution spanning the Caucasus, the western and central Asian mountains and the Himalaya to western China. GBIF (some 4,164 occurrences) records it from the Caucasus (Georgia, Azerbaijan, Turkey, Iran), China, India, Nepal, Pakistan and Russia, alongside extensive cultivated material across Europe and North America. It grows in moist temperate and montane mixed forest, often along streams and on north-facing slopes. The photographed tree is from the Mo-Chu valley in western Bhutan at about 1,600 m, in May, within its eastern Himalayan range of roughly 1,500–3,000 m.

It is a medium to large tree to 20–30 m with smooth greyish bark and reddish young shoots. The leaves are opposite, palmately 5–7-lobed, the lobes triangular-ovate, long-acuminate and entire-margined, glabrous and bright green, turning clear yellow in autumn. The inflorescence is a terminal erect corymb of small yellowish-green flowers. The fruit is the characteristic acerine double samara, the two nutlets bearing widely divergent, nearly horizontally spreading wings.

Acer cappadocicum is variable over its great range and several subspecies are recognised, the Himalayan and Chinese populations sometimes segregated as subsp. sinicum and others. Now placed in Sapindaceae (formerly Aceraceae), it is a widespread and non-threatened species, valued ornamentally for its autumn colour. Its trans-Asian range makes it a classic example of the temperate-forest floristic link between the Himalaya, Central Asia and the Caucasus. The input wp_link erroneously references A. campbellii.

Author: Gled. · Sources: POWO (Kew), Flora of China Vol. 11, Flora of Bhutan Vol. 2, GBIF, van Gelderen et al.: Maples of the World (1994)

Sapindaceae

Acer caudatum

by G & P Jürgens

Wall.

BhutanPG2011 59
Bhutan Jakar, 2100m June
BhutanPG2011 60
Bhutan Jakar, 2100m June

Description

Acer caudatum is a deciduous maple of the Himalaya and the mountains of China, distributed through China, Nepal, India, Bhutan, Myanmar, Afghanistan and into Russia, with over two thousand recorded occurrences across this broad range. It is a tree of moist temperate and subalpine forest, growing in mixed broad-leaved and conifer woodland, along ravines and on cool shaded slopes on humus-rich soils. In Bhutan it occurs in the middle montane belt, as illustrated by the collection near Jakar in the Bumthang region at about 2100 m in June, when the trees are in full leaf and flower.

The species is a small to medium-sized tree with smooth greyish bark and slender branchlets. The leaves are opposite, long-petiolate and orbicular in outline, palmately five- to seven-lobed with the lobes ovate-acuminate and the margins sharply and doubly serrate, often softly hairy on the veins beneath. The inflorescence is an erect terminal raceme or narrow panicle bearing numerous small yellowish-green flowers. The fruit is the typical maple double samara, the two nutlets each bearing a membranous wing, the wings spreading at a wide to nearly horizontal angle to enable anemochorous dispersal of the seeds.

Acer caudatum, described by Wallich and now placed in Sapindaceae following the merger of the former Aceraceae, is a variable species classified within section Spicata, the group of maples with erect spike-like inflorescences. Several geographical varieties have been recognised across its range, reflecting its wide montane distribution. The species is a normal component of Himalayan temperate forest and is not threatened, contributing to autumn colour and, through its winged fruits, to the regeneration dynamics of mid-elevation woodland.

Author: Wall. · Sources: POWO (Kew), GBIF, Flora of China Vol. 11, Flora of Bhutan Vol. 2, Flora of Nepal, Flora of Pakistan, van Gelderen et al. Maples of the World

Sapindaceae

Acer oblongum

by GP Jürgens

Wall. ex DC.

Bhutan2014 657
Bhutan Wangdi-Phodrang 2300m, May

Description

Acer oblongum, the evergreen or Himalayan maple, is a broadly distributed tree of the southern and eastern Himalaya and the mountains of southern and central China, recorded by GBIF from China, India, Nepal, Bhutan, Myanmar, Thailand, Vietnam, Pakistan and Taiwan (with numerous cultivated records in Europe and North America) across some 3,600 georeferenced occurrences. It grows in subtropical to warm-temperate broadleaf and mixed forest, on hill slopes, ridges, riverine forest and forest margins, generally between about 600 and 2,500 m. The photographed tree from Wangdi-Phodrang in western Bhutan at around 2,300 m in May represents its upper montane occurrence, where it flowers in spring with the flush of new growth.

Unusually for a maple, A. oblongum is evergreen or semi-evergreen, and equally atypical are its leaves, which are simple, entire and unlobed, oblong-lanceolate to ovate-oblong, leathery, glossy dark green above and conspicuously glaucous or whitish beneath, with pinnate or triplinerved venation rather than the palmate lobing characteristic of most of the genus. The flowers are small, greenish-yellow, andromonoecious or polygamous, borne in corymbose or paniculate clusters. The fruit is the typical maple double samara, the two nutlets each bearing a membranous wing; in this species the wings are spreading at an acute to nearly parallel angle, adapted to autorotating wind dispersal.

Acer oblongum is treated within section Pentaphylla (series Trifida) of the genus Acer, now placed in an enlarged Sapindaceae following the merger of the former Aceraceae. Its entire, evergreen leaves make it one of the most distinctive of the Asian maples and a noteworthy example of foliar reduction within a predominantly palmately-lobed genus, of interest to studies of leaf-form evolution. The species is widespread, locally common, and valued horticulturally and for its timber; it is not considered globally threatened, although particular regional populations face pressure from forest clearance.

Author: Wall. ex DC. · Sources: POWO (Kew), GBIF, Flora of China Vol. 11, Flora of Bhutan Vol. 2, Flora of Nepal, Flora of Pakistan, van Gelderen, de Jong & Oterdoom: Maples of the World

Ranunculaceae

Aconitum heterophylloides

by GP Jürgens

Stapf

Bhutan2012 177
Bhutan Haar-Valley, 3500m September
Bhutan2012 327
Bhutan Dochu-La, 3200m September

Description

Aconitum heterophylloides is an eastern Himalayan monkshood distributed across Nepal, India, Bhutan and adjacent China, a comparatively narrowly known species with around 68 GBIF occurrences. It grows in subalpine and alpine habitats, on open grassy slopes, scrub margins, forest clearings and damp meadows in the upper temperate to subalpine zone, flowering late in the season. The images document it in Bhutan in the Haar Valley at about 3500 m and at Dochu-La near 3200 m, both in September, when its blue-purple hoods appear among the autumn meadow vegetation.

It is an erect perennial herb arising from paired tuberous roots, with a slender, often somewhat flexuous stem. The leaves are alternate, palmately divided into several lobes, the lower long-petiolate and the upper sessile, with the segments toothed. The inflorescence is a lax terminal raceme of zygomorphic flowers; the conspicuous perianth consists of petaloid sepals, the uppermost forming a tall, helmet- or hood-shaped galea that arches over the two concealed nectariferous petals. The flowers are violet-blue, and the fruit is a cluster of several many-seeded follicles.

Aconitum heterophylloides belongs to the large Sino-Himalayan radiation of the genus, which is taxonomically complex and includes many intergrading montane species; it is allied to the A. heterophyllum group. Like other monkshoods the plant contains diterpenoid alkaloids and is highly toxic, while the hooded flowers are adapted for buzz- and tongue-pollination by bumblebees foraging late in the alpine season. Several Himalayan Aconitum are heavily harvested for medicinal use, making range-restricted species potentially vulnerable to overcollection.

Author: Stapf · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora of Nepal, Tamura's treatment of Ranunculaceae

Ranunculaceae

Aconitum hookeri

by GP Jürgens

Stapf

Sikkim2003 249 P343
Sikkim Dzongri 4300m, August
Sikkim2003 251 G345
Sikkim Dzongri 4300m 08.2003
Sikkim2003 250 G344
Sikkim Dzongri 4200m, August

Description

Aconitum hookeri is an alpine perennial of the eastern Himalaya, recorded from Nepal, China and India (NP, CN, IN, with further records), with around 96 documented occurrences. It inhabits open alpine meadows, grassy slopes, stony pastures and the margins of dwarf scrub in the high alpine zone, generally between about 4000 and 4800 m. The collections cited were all made at Dzongri in Sikkim, at 4200 to 4300 m in August, an elevation and late-summer flowering season fully characteristic of the species, where it grows in herb-rich turf above the treeline among the rolling alpine pastures of the upper Rathong valley.

The plant is a low, erect to ascending perennial herb arising from a tuberous, paired rootstock. The leaves are deeply palmately divided into narrow, again-lobed segments, dark green and mostly basal or on the lower stem. The inflorescence is a few-flowered terminal raceme of large, showy, deep blue to violet flowers. As in all Aconitum the flowers are strongly zygomorphic: the uppermost of the five petaloid sepals is enlarged into a tall, helmet-shaped hood (the galea) arching over two long-clawed nectariferous petals concealed within, the remaining sepals spreading. The numerous stamens surround several free carpels that mature into a cluster of follicles releasing winged or angled seeds.

Aconitum (monkshood; subfamily Ranunculoideae of the Ranunculaceae) is a large genus of the northern temperate and alpine zones, richly represented in the Sino-Himalaya. The hooded flowers are specialised for pollination by long-tongued bumblebees, which alone can reach the nectaries within the galea. Like its congeners A. hookeri contains highly toxic diterpenoid alkaloids of the aconitine type, rendering the whole plant dangerously poisonous yet of interest in traditional medicine. Restricted to high alpine grassland, it is locally frequent and not presently of conservation concern.

Author: Stapf · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Aconitum monograph (Tamura/Rapaics, Ranunculaceae)

Ranunculaceae

Aconitum lethale

by GP Jürgens

Griff.

Sikkim2003 440 P612
Sikkim Chopta Valley 3900m August
Sikkim2003 441 P613
Sikkim Chopta Valley 3900m August
Bhutan2012 39
Bhutan Shele-La, 3600m September
Bhutan2015 21
Bhutan2015 22
Bhutan Dochu-La 3000m, October
Bhutan2012 176
Bhutan Haar-Valley 3500m, September

Description

Aconitum lethale is an eastern Himalayan monkshood restricted to Nepal, India and Bhutan, with about 176 GBIF records concentrated in Sikkim and Bhutan. It is a plant of the upper subalpine and alpine zone, growing among tall-herb meadows, rhododendron and juniper scrub, and along moist, open slopes. The cited collections trace its habitat closely: the Chopta Valley in Sikkim at around 3900 m in August, and several Bhutanese sites including Shele-La at about 3600 m, the Haar Valley at 3500 m and Dochu-La near 3000 m, flowering from late summer into October. It favours cool, humid, well-drained mountain soils where the monsoon sustains lush herbaceous growth.

The plant is an erect perennial herb arising from tuberous roots, with a leafy stem bearing palmately divided, deeply lobed leaves whose segments are further incised. The inflorescence is a terminal raceme or panicle of the characteristic zygomorphic flowers, in which the upper sepal is enlarged into a tall, helmet-shaped or hooded galea concealing two long-clawed nectaries; the flowers are typically deep blue to violet. Numerous stamens surround several free carpels, which ripen into a cluster of dehiscent follicles releasing winged or angular seeds.

Described by Griffith, A. lethale is, as both its epithet and generic affinity warn, intensely poisonous, containing diterpenoid alkaloids of the aconitine type throughout the plant and especially in its tubers. Such alkaloids underlie the cautious medicinal use of Himalayan aconites in traditional pharmacopoeias. As a narrow-range endemic of the eastern Himalaya, it warrants attention to grazing pressure and habitat change, though it remains locally frequent within its restricted distribution.

Author: Griff. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Tamura's treatment of Aconitum

Ranunculaceae

Aconitum nakaoi

by G & P Jürgens

Tamura

Bhutan2012 288
Bhutan Shele-La, 4100m September

Description

Aconitum nakaoi is a high-alpine monkshood distributed across the eastern Himalaya and the south-eastern Tibetan plateau margin, recorded from Bhutan, China (Xizang and adjacent Yunnan), Nepal and northern India. Its modest documentary record of around 21 georeferenced occurrences reflects both its restricted range and the difficulty of botanizing the steep upper screes and meadows it favours. The species inhabits open alpine turf, the margins of dwarf-shrub thickets and damp stony slopes, typically between about 3,800 and 4,500 m. The photographed plant from Shele-La in Bhutan at 4,100 m, flowering in September, is characteristic of its late-season anthesis in the cool, monsoon-influenced uplands where snowmelt and persistent humidity sustain the short growing season.

The plant is a perennial herb arising from small paired tuberous roots, with slender, often decumbent to ascending stems. The leaves are palmately divided into narrow, deeply incised segments, glabrous to thinly pubescent, the basal leaves long-petiolate and the cauline ones progressively reduced. The inflorescence is a lax few-flowered raceme bearing the zygomorphic, helmet-shaped flowers typical of the genus; the upper sepal forms a high, narrowly conical to galeate hood enclosing two long-clawed nectariferous petals, the colour ranging from violet-blue to dull purplish. The fruit is a cluster of several erect follicles releasing winged seeds.

Like all Aconitum, the species contains diterpenoid alkaloids and is highly toxic. It belongs to the taxonomically intricate Himalayan radiation of section Aconitum, where narrow endemics and clinal variation complicate species delimitation. Though not formally assessed as threatened, its narrow altitudinal band makes it sensitive to upward shifts of the treeline and to grazing pressure on alpine pastures.

Author: Tamura · Sources: POWO (Kew), Flora of China Vol. 6, Flora of Bhutan Vol. 1, GBIF, Tamura: Ranunculaceae in Die natürlichen Pflanzenfamilien

Ranunculaceae

Aconitum naviculare

by GP Jürgens

Stapf

Sikkim2003 256 P351
Sikkim Dzongri 4200m August

Description

Aconitum naviculare is a high-alpine monkshood of the eastern and central Himalaya, ranging from Nepal through Sikkim and northern India into Bhutan, south-western China (Xizang) and northern Myanmar; its modest tally of around 110 georeferenced occurrences (CN, NP, BT, IN, MM) reflects its specialised montane niche. It occupies open alpine meadows, screes, moist turf and rocky slopes at high elevation, typically between about 3500 and 4800 m. The plant photographed at Dzongri in Sikkim at 4200 m in August, flowering at the height of the monsoon-influenced alpine summer, exemplifies its cold, exposed habitat near the upper limit of vascular plant growth.

It is a small perennial herb arising from a slender tuberous rootstock, with an erect or somewhat flexuous stem usually under 30 cm. The leaves are palmately divided into narrow, deeply cut segments. The flowers are few and borne in a lax terminal raceme; as in all Aconitum the five petaloid sepals are zygomorphic, the uppermost forming the characteristic helmet or hood (galea), here narrowly boat-shaped (navicular, whence the epithet), bluish-purple and often paler within. Two long-clawed nectariferous petals are concealed beneath the hood, with numerous stamens and three to five free carpels ripening into a cluster of follicles containing winged seeds.

Aconitum naviculare belongs to subgenus Aconitum and is a noted constituent of Himalayan alpine flora, valued and harvested in Tibetan and folk medicine as "Bonga" for its diterpenoid alkaloids, which render the whole plant highly toxic. Such harvesting, combined with its restricted high-altitude range, raises local conservation concern, although it remains frequent within intact alpine grassland.

Author: Stapf · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora of Nepal, Stapf's monograph of the Asiatic species of Aconitum