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.

Apocynaceae

Hoya polyneura

by G & P Jürgens

Hook.f.

Bhutan2015 202
Bhutan Zhemgang 1000m, October
Bhutan2012 764
Bhutan Zemgang 1400m, October

Description

Hoya polyneura Hook.f. is an epiphytic vine of the eastern Himalaya and adjoining ranges, recorded from India, Bhutan, Nepal and China, with disjunct material from Japan; the GBIF total of about 59 occurrences reflects its scattered, locally frequent presence in humid mid-montane forest. It grows as an epiphyte or lithophyte on mossy trunks and damp rock faces in subtropical to warm-temperate broad-leaved evergreen forest, broadly between 800 and 2000 m. The photographed plants from Zhemgang in central Bhutan at about 1000 and 1400 m, flowering in October, illustrate its occurrence in the moist, shaded forest interior of the southern Bhutanese foothills.

The species is a slender, twining to pendent epiphytic subshrub with thin, flexible stems rooting at the nodes and exuding milky latex when cut. The leaves are opposite, distinctly thin-textured and elliptic to ovate, with a prominent, fish-bone-like venation of fine, parallel lateral nerves arching to the margin — the feature giving the epithet polyneura. The inflorescence is an axillary, umbelliform cyme of few to several flowers; each has a fleshy, reflexed, five-pointed corolla, cream to yellowish often marked with red, surmounted by the waxy, star-shaped, glistening staminal corona typical of the genus. Pollen is aggregated into paired pollinia, and the fruit is a slender paired follicle releasing comose seeds.

Hoya (Apocynaceae, subfamily Asclepiadoideae) is a large palaeotropical genus distinguished by its waxy, coronate flowers and pollinarial pollination. H. polyneura is among the most distinctive Himalayan species owing to its conspicuously veined, almost translucent leaves, a prized character in cultivation where it is grown as the "fishtail Hoya." As a forest-dependent epiphyte it is sensitive to deforestation and over-collection for the ornamental trade, though formally unassessed and locally not uncommon within intact montane forest.

Author: Hook.f. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora of British India, Surveswaran et al. — Phylogeny and revision of Hoya

Hydrangeaceae

Hydrangea anomala

by G & P Jürgens

D. Don

Bh2008 472 P734
Bhutan Samtengang, 2040m April
Bh2008 473 P736
Bhutan Samtengang, 2040m April
Nepal 1994 251 ergebnis
Ost-Nepal Milka-Danda 2400m April 

Description

Hydrangea anomala is a climbing shrub of temperate montane forests, one of the most widely recorded species in this group with over 2000 GBIF occurrences. Its native range extends along the Himalaya and through China, Taiwan, Myanmar, Japan and Korea, and it is widely grown in temperate gardens, generating cultivated records across Europe, North America and beyond. It inhabits moist broadleaved and mixed forest, climbing tree trunks and rock faces by adventitious aerial roots. It was photographed at Samtengang in Bhutan at about 2040 m and on the Milka-Danda ridge of eastern Nepal at about 2400 m, both in April, when the flat inflorescences open in the spring forest.

It is a deciduous, root-climbing liana with peeling, reddish-brown bark, attaching by clinging rootlets along the stems. The leaves are opposite, ovate to elliptic, acuminate, serrate and glabrescent, on slender petioles. The inflorescence is a broad, flattened corymb in which numerous small fertile flowers, with minute whitish petals and stamens, are surrounded by a marginal ring of showy sterile flowers bearing three to four enlarged, petaloid white sepals. The fruit is a small, ribbed, urn-shaped capsule opening between the persistent styles to release many minute seeds.

Hydrangea (Hydrangeaceae) comprises shrubs, climbers and small trees of east Asia and the Americas; the climbing species, including H. anomala, are sometimes placed in subgenus Calyptranthe, and H. petiolaris is often regarded as an allied subspecies. Long cultivated as an ornamental climber, H. anomala is widespread and secure across its native range, and is of biogeographic interest within the disjunct Sino-Himalayan to Japanese temperate forest flora.

Author: D. Don · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, McClintock's monograph of Hydrangea (Hydrangeaceae)

Hydrangeaceae

Hydrangea febrifuga 

by GP Jürgens

(Lour.) Y.De Smet & C.Granados

Sikkim2003 52 P71^
Sikkim above Yoksam 2300m, August

Nepal 2001 431 ergebnis ergebnis
Nepal (Gorkha) Laprak 2000m, May

Description

Hydrangea febrifuga, long familiar under the name Dichroa febrifuga, is a widely distributed shrub of subtropical and warm-temperate Asia, ranging from the Himalaya (Nepal, Sikkim, Bhutan, northeast India) eastward through southern China, Myanmar, Thailand and Indochina to Malesia and the Philippines. It inhabits moist, shaded forest, ravines and streamsides, forming part of the evergreen broad-leaved understorey. It is recorded from low to mid elevations; the populations shown above Yoksam in Sikkim at 2,300 m in August and at Laprak in the Gorkha region of Nepal at 2,000 m in May span its typical mid-montane range in humid forest.

The plant is an erect, much-branched shrub with subquadrangular, often purplish young stems. The leaves are opposite, elliptic to oblong-lanceolate, with a serrate margin, acuminate apex and a glabrous to sparsely pubescent surface. The inflorescence is a terminal or axillary corymbose to paniculate cyme bearing numerous small bisexual flowers; the calyx is shortly toothed and the corolla blue to violet or whitish with thick, valvate petals, the stamens conspicuous. Distinctively for the family, the fruit is a fleshy, indigo-blue berry crowned by the persistent calyx and containing many minute seeds.

Molecular phylogenetic work has shown the segregate genus Dichroa to be nested within Hydrangea, prompting the recombination as Hydrangea febrifuga by De Smet and Granados; the basionym traces to Loureiro's original description of Lourea. The species is of long-standing ethnomedical importance: its roots and leaves, rich in the alkaloid febrifugine, have been used in traditional Chinese and Himalayan medicine against malaria and fevers, a property reflected in the epithet. It remains common and is not considered threatened.

Author: (Lour.) Y.De Smet & C.Granados · Sources: POWO (Kew), Flora of China Vol. 8, Flora of Bhutan Vol. 1, GBIF, De Smet et al.: Hydrangea phylogeny (TAXON)

Hydrangeaceae

Hydrangea heteromalla

by G & P Jürgens

D. Don

Sikkim2011 179
Sikkim Lachen 2760m, June

Description

Hydrangea heteromalla is a deciduous shrub or small tree of the Himalaya and central China, with GBIF returning over 1600 occurrences spanning its native range in China, Nepal, India, Bhutan and Myanmar as well as numerous cultivated and naturalised records from Europe and North America. In the wild it grows in cool temperate forest, on open slopes, forest margins, ravines and shrubberies, typically between about 1500 and 3500 m. The plant photographed near Lachen in northern Sikkim at about 2760 m, flowering in June, occupies the moist temperate montane belt where the species is a frequent understorey and edge shrub.

The plant has stout, spreading branches with peeling bark and opposite leaves that are ovate to elliptic, acuminate, finely serrate, and characteristically discolorous, dark green above and densely pale-tomentose to whitish beneath, the indumentum giving the epithet heteromalla. The inflorescence is a broad, flat-topped to slightly domed corymb bearing many small fertile flowers surrounded at the margin by larger, showy, sterile ray-florets with four enlarged white sepaloid segments. The fertile flowers are small, white, with five petals and numerous stamens. The fruit is a small ribbed capsule opening at the apex to release numerous tiny seeds.

Hydrangea heteromalla is a variable and widespread species, the subject of much horticultural selection and the source of cultivated forms grown for their lacecap inflorescences, which explains its scattered records across temperate gardens worldwide. Within Hydrangea section Hydrangea it represents the principal Himalayan-Chinese montane lineage. Ecologically the marginal sterile florets serve to attract pollinators to the inconspicuous fertile flowers. The species is common and not threatened, and its wide ecological amplitude and ornamental value have ensured both its persistence in the wild and its global cultivation.

Author: D. Don · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, McClintock "A Monograph of the Genus Hydrangea", Annotated Checklist of the Flowering Plants of Nepal

Hydrangeaceae

Hydrangea macrophylla

by G & P Jürgens

(Thunb.) Ser.

Bhutan2015 285
Bhutan Zhemgang 910m, October

Description

Hydrangea macrophylla is a deciduous shrub of East Asian origin, now among the most widely cultivated ornamental hydrangeas worldwide; this is reflected in its very large GBIF record (over 16,000 occurrences) spanning Japan, China, Korea, much of Europe, the Americas, Australasia and beyond, where most points represent garden or naturalised plants. In the Himalaya it occurs chiefly in cultivation and around settlements, growing in moist, humus-rich, partially shaded ground at low to mid elevations. The documented plant from Zhemgang in Bhutan at 910 m in October indicates such a subtropical montane setting, flowering and fruiting late in the season in the warm-temperate belt.

The species is a rounded, much-branched shrub with stout, glabrous stems and large, opposite, broadly ovate to elliptic leaves that are coarsely serrate, glossy and somewhat fleshy. The inflorescence is a broad, flattened to globose terminal corymb; in wild and lacecap forms the small fertile flowers occupy the centre while showy sterile flowers with four enlarged, petaloid sepals form the margin, whereas cultivated mopheads are dominated by sterile flowers. Corolla colour ranges from white through pink to blue, the latter influenced by soil acidity and available aluminium. The fruit is a small ribbed capsule with numerous minute seeds.

Within Hydrangeaceae the species belongs to the mophead and lacecap group and has given rise to innumerable cultivars. Its sterile marginal flowers act as visual attractants for pollinators of the inner fertile florets, and its pigment chemistry makes flower colour a notable indicator of substrate pH. Wild populations are restricted to coastal Japan, while elsewhere occurrence is overwhelmingly anthropogenic.

Author: (Thunb.) Ser. · Sources: POWO (Kew), GBIF, Flora of China Vol. 8, Flora of Bhutan Vol. 1, McClintock A Monograph of the Genus Hydrangea

Hydrangeaceae

Hydrangea stylosa

by G & P Jürgens

Hook. f. & Thomson

Bhutan2012 692
Bhutan Galephu, 850m September
Bh09 216 G363
Bhutan Dochu-La, 3000m June
Bh09 217 P364 2
Bhutan Dochu-La, 3000m June

Description

Hydrangea stylosa Hook.f. & Thomson is a Sino-Himalayan shrub recorded by GBIF from China, Bhutan, India, Vietnam and Japan, with cultivated occurrences from Canada and New Zealand, totalling about 85 records. It occupies a broad altitudinal range in moist broad-leaved and mixed forest, thickets and forest margins, on shaded slopes and along ravines. The Bhutanese material spans this amplitude strikingly, with collections from Galephu at 850 m in September and from the Dochu-La at 3000 m in June, showing occurrence from low submontane forest up into the cool temperate zone.

It is a deciduous shrub with terete branches, the young growth often pubescent and the bark exfoliating on older stems. The leaves are opposite, ovate to oblong-lanceolate, with a serrate margin, an acuminate apex and pinnate venation, pilose along the veins beneath. The inflorescence is a terminal corymbose cyme bearing two kinds of flowers: numerous small fertile flowers with minute petals, and a marginal ring of showy sterile flowers whose enlarged, petaloid white to pinkish sepals attract pollinators. The fertile flowers are notable for their elongate, persistent styles, emphasised by the epithet stylosa; the fruit is a small ribbed capsule opening between the styles.

Within Hydrangea, H. stylosa belongs to the lacecap-type species, in which marginal sterile flowers advertise the fertile centre to insects. Its distribution forms part of the eastern Himalayan to Sino-Japanese floristic continuum, and the species is of horticultural interest, accounting for the cultivated records beyond its native range. As a forest understorey shrub it depends on humid montane woodland.

Author: Hook. f. & Thomson · Sources: POWO (Kew), GBIF, Flora of Bhutan Vol. 1, Flora of China Vol. 8, McClintock monograph of the genus Hydrangea, Flora of Nepal

Araliaceae

Hydrocotyle javanica

by G & P Jürgens

Thunb.

Bhutan2015 150
Bhutan Zhemgang 900m, October

Description

Hydrocotyle javanica is a widespread perennial herb of tropical and subtropical Asia and the western Pacific, recorded from the Himalaya (Nepal, NE India, Bhutan) through southern China, Taiwan, Japan and Korea to Sri Lanka, Myanmar, Indochina, Malesia, the Philippines, New Guinea, Australia and Fiji; with 2,061 GBIF occurrences it is among the better-documented members of its genus. It favours moist, shaded ground along streams, forest floors, seepage banks and damp roadside verges. The Bhutan record from Zhemgang at about 900 m in October places it in warm, humid subtropical forest, where it grows as a creeping ground cover.

It is a creeping to ascending herb rooting at the nodes, with slender, often pilose stems. The leaves are alternate, long-petioled, orbicular to reniform in outline, 2–7 cm wide, palmately 5–7-lobed with the lobes again toothed, cordate at the base, and frequently bearing scattered hairs. The inflorescences are condensed simple umbels, sometimes verticillate along the stem, on peduncles shorter than the petioles; the minute flowers are whitish to greenish, with five petals and an inferior bicarpellate ovary. The fruit is a small, laterally compressed schizocarp, broader than long, the mericarps with conspicuous lateral ribs.

Long placed in Apiaceae, Hydrocotyle is now segregated into Araliaceae (Hydrocotyloideae) on molecular grounds, so the input family is botanically defensible. GBIF lists the name as accepted. The species is highly variable across its enormous range, and several infraspecific taxa have been described; it is common, weedy and of no conservation concern.

Author: Thunb. · Sources: POWO (Kew), Flora of China Vol. 14, Flora of Bhutan Vol. 2, GBIF, Pimenov & Leonov: The Genera of the Umbelliferae (1993)

Fabaceae

Hylodesmum laxum

by G & P Jürgens

(DC.) H.Ohashi & R.R.Mill

Bhutan2012 572
Bhutan Wangdi 2700m, September
Bhutan2012 573
Bhutan Wangdi 2700m, September

Description

Hylodesmum laxum is a widely distributed forest herb of warm-temperate and subtropical Asia, recorded from Japan, China, Taiwan, the Philippines, Indonesia, Papua New Guinea, India, Vietnam, Sri Lanka, Thailand, Nepal and Bhutan, with some 740 georeferenced occurrences. It is a characteristic understorey element of moist broad-leaved and mixed evergreen forests, favouring shaded slopes, forest margins and streamside thickets on humus-rich soils. In the eastern Himalaya it ascends to the middle montane belt, as illustrated by the material gathered near Wangdi in central Bhutan at about 2700 m in September, when it flowers and fruits in the post-monsoon season.

The species is a perennial herb with erect or ascending, slender, ridged stems arising from a woody rootstock. The leaves are pinnately trifoliolate and crowded toward the stem apex, the terminal leaflet rhombic-ovate to elliptic and larger than the lateral ones, acuminate and entire, thinly membranous and sparsely appressed-pubescent. The inflorescence is a lax, elongate terminal raceme or panicle bearing small papilionaceous flowers with a pink to pale purple corolla, the standard obovate and the keel obtuse. The fruit is a flattened, stipitate loment constricted between the segments, the articles covered with uncinate hairs that promote epizoochorous dispersal.

The genus Hylodesmum was segregated from Desmodium by Ohashi and Mill to accommodate species with stipitate, deeply constricted loments and a forest-herb habit, and H. laxum is among its more widespread members. Its very broad transcontinental range, spanning the Himalaya to the western Pacific, points to effective long-distance dispersal by the hooked fruit articles. Locally common and of no immediate conservation concern, its populations nonetheless remain dependent on intact forest cover, and the species is a useful indicator of relatively undisturbed montane woodland.

Author: (DC.) H.Ohashi & R.R.Mill · Sources: POWO (Kew), GBIF, Flora of China Vol. 10, Flora of Bhutan Vol. 1, Flora of Nepal, Ohashi & Mill revision of Hylodesmum (Desmodium group)

Apiaceae

Hymenidium benthamii

by GP Jürgens

(Wall. ex DC.) C.B. Clarke

BhutanPG2011 365
Bhutan Jule-Tso 4150m, June
Sikkim2003 159 P212
Sikkim Dzongri 3900m, August
Sikkim2003 160 P213
Sikkim Dzongri 3900m, August

Description

Hymenidium benthamii is a robust alpine umbellifer of the high Himalaya, distributed through Nepal, China, India, Myanmar and Bhutan (gbif_countries: NP, CN, IN, MM, BT), with about 181 GBIF occurrences. It grows in alpine meadows, damp grassy slopes, rocky pastures and streamside flushes above the treeline, where it is a characteristic herb of the moist eastern Himalayan uplands. The illustrated collections span Jule-Tso in Bhutan at about 4150 m, flowering in June, and Dzongri in Sikkim at about 3900 m in August, documenting its occupation of the cool subalpine to alpine zone through the monsoon season.

The plant is a stout perennial arising from a thickened taproot and crown, with erect, ribbed, often hollow stems. The leaves are largely basal, long-petiolate and two- to three-times pinnately divided into toothed or further-dissected segments, the petioles sheathing at the base. The inflorescence is a large, flat-topped compound umbel subtended by a conspicuous involucre of broad, often membranous-margined bracts, a feature recalling the genus name Hymenidium; the small flowers are white to pinkish with five petals. The fruit is a dry schizocarp splitting into two ribbed mericarps, the ridges and oil-canals (vittae) providing key taxonomic characters.

Long known under Pleurospermum benthamii, the species, as the wp_link itself preserves, has been transferred to Hymenidium following revisionary work that dismembered the broadly construed Pleurospermum on molecular grounds. It belongs to the conspicuous-bracted alpine Apiaceae of the Sino-Himalaya, a group much used in regional ethnomedicine. Widespread across its montane range, it is of no conservation concern.

Author: (Wall. ex DC.) C.B. Clarke · Sources: POWO (Kew), GBIF, Flora of Nepal, Flora of China, Annotated Checklist of the Flowering Plants of Nepal, Pimenov & Kljuykov revision of Pleurospermum and allied genera

Hypericaceae

Hypericum choisianum

by GP Jürgens

Wall. ex N.Robson

BhutanPG2011 824 01 01
Bhutan Luksor, 2800m July
BhutanPG2011 695 01 01
Bhutan Luksor, 2800m July
Sikkim2003 378 P531
Sikkim Tista valley 3400m August

Description

Hypericum choisianum (correctly H. choisyanum) is a handsome shrubby St John's wort of the Himalaya, distributed from Nepal eastward through India, Sikkim, Bhutan and into southwestern China, with outlying records from Myanmar; cultivated and naturalised material accounts for occurrences in Britain, Ireland and Vietnam, contributing to a GBIF total of over two hundred records. It inhabits open temperate forest, forest margins, scrub, banks and rocky slopes, typically between about 1800 and 3600 m. The plants documented from Luksor in Bhutan at 2800 m in July and from the Tista valley in Sikkim at 3400 m in August reflect both its broad elevational tolerance and its mid-to-late summer flowering, when the large golden blooms are conspicuous along forest edges and clearings throughout the monsoon season.

The plant is an evergreen or semi-evergreen shrub of one to two metres, with arching reddish branches and opposite, ovate to oblong-lanceolate, sessile or clasping leaves that are slightly glaucous beneath and dotted with translucent glands. The flowers are large and showy, solitary or few in terminal cymes, with five broad, bright golden-yellow petals that are often somewhat incurved to give a cupped, almost globose bloom. The numerous stamens are united into five fascicles, and the styles are five, free and spreading. The superior, five-locular ovary develops into a leathery to slightly fleshy capsule that dehisces to release many small seeds; the glandular tissue throughout the plant contains the characteristic hypericin and related compounds.

Hypericum, here placed in the Hypericaceae (sometimes treated within a broadly defined Clusiaceae), reaches notable diversity in the Sino-Himalaya, and H. choisyanum belongs to the large-flowered shrubby section Ascyreia, several members of which are valued as garden ornamentals for their bold yellow flowers and hardiness. Described by N. Robson, who monographed the genus, it is part of a closely allied complex of Himalayan shrubs distinguished by subtle differences in leaf shape, stamen fascicles and capsule form. As a common, ecologically adaptable species spanning a wide range and elevation, it is of no conservation concern, and its frequency along disturbed forest margins reflects considerable tolerance of moderate human modification.

Author: Wall. ex N.Robson · Sources: POWO (Kew), GBIF, Flora of China Vol. 13, Flora of Bhutan Vol. 1 Part 2, Flora of Nepal, Studies in the genus Hypericum (Norman Robson, Bulletin of the British Museum)