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.

Euphorbiaceae

Euphorbia royleana

by GP Jürgens

Boiss.

Bhutan2014 202
Bhutan Trashyangtse 2100m, May
Bhutan2014 203
Bhutan Trashyangtse 2100m, May
Nepal 2001 516 ergebnis ergebnis
Nepal (Gorkha) Mulabari 1340m, May

Description

Euphorbia royleana is a succulent, tree-like spurge of warm, dry valleys across the Himalaya and adjacent regions. With 148 GBIF occurrences, it ranges through Nepal, India, China, Pakistan and Bhutan, with cultivated or introduced records noted elsewhere including Belgium, Egypt and the United States, reflecting its use as an ornamental and hedge plant. It is characteristic of hot, semi-arid slopes, rocky hillsides and degraded scrub in the subtropical to lower temperate zone, often on south-facing rain-shadow exposures. It was recorded at Trashyangtse in Bhutan at about 2100 m and at Mulabari in Gorkha, Nepal, at about 1340 m, both in May.

It is a stout, cactus-like succulent shrub or small tree with a short woody trunk and erect, candelabriform branches that are fleshy, grey-green and obtusely five- to seven-angled. Paired, short stipular spines arise on the angles, subtending small, fugacious leaves clustered near the branch tips. As in all Euphorbia the inflorescence is a cyathium: cup-like involucres bearing nectar glands enclose the reduced unisexual flowers, here borne in small cymose clusters and yielding the abundant caustic white latex typical of the genus. The fruit is a three-lobed capsule splitting into three mericarps.

Euphorbia (Euphorbiaceae) is among the largest of all plant genera, and E. royleana belongs to its succulent, xerophytic Old World element adapted to seasonal aridity. Long valued in the region for living fences and traditional medicine, it is widely planted, and its milky latex is irritant and toxic. The species is not of conservation concern, being common and frequently cultivated, but it is an important structural and biogeographic component of dry inner-Himalayan valley vegetation.

Author: Boiss. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Pakistan, Annotated Checklist of the Flowering Plants of Nepal, Boissier's monograph of Euphorbia in de Candolle's Prodromus

Euphorbiaceae

Euphorbia sikkimensis

by G & P Jürgens

Boiss.

Nepal 2001 302 ergebnis ergebnis
Nepal (Gorkha) Lambra Kharka 3100m, May
Nepal 2001 301 ergebnis
Nepal (Gorkha) Lambra Kharka 3100m, May
Nepal 97 86 P146
Nepal Tankhu 2100m April

Description

Euphorbia sikkimensis is a robust herbaceous spurge distributed across the eastern and central Himalaya, from central Nepal through Sikkim, Bhutan, and northeast India into southern China (Xizang, Yunnan), with peripheral records from Myanmar, Laos, and Vietnam. It occurs in subalpine meadows, forest clearings, scrub margins, and open hillsides at elevations of 1,800–3,500 m. The species has been documented from the Gorkha district of Nepal at Lambra Kharka at 3,100 m in May and near Tankhu at 2,100 m in April, indicating a broad elevational amplitude and early-season phenology at lower altitudes.
The plant is a stout, erect perennial herb, 30–80 cm tall, with thick, fleshy rootstock and unbranched or sparingly branched stems that exude copious white latex when cut. Leaves are alternate, sessile, linear-lanceolate to oblanceolate, 8–15 cm long and 1–2.5 cm wide, with a prominent pale midrib, entire margins, and a glaucous undersurface. The inflorescence is a terminal, compound cyathium typical of the genus, with a broad umbel of 4–8 primary rays, each ray subtended by obovate, yellowish-green floral bracts. The cyathia bear crescent-shaped glands with short horns. The fruit is a smooth, trilocular capsule approximately 6–8 mm in diameter, explosively dehiscent at maturity, with carunculate seeds.
Euphorbia sikkimensis was described by Boissier from Sikkim collections and belongs to Euphorbia subgenus Esula, a predominantly Eurasian clade of herbaceous spurges. It is notable for its striking appearance in early spring, when the bright red or pink-tinged new stems contrast with the yellowish-green inflorescences. The species has gained horticultural recognition in temperate gardens and is increasingly cultivated as an ornamental perennial in Europe. Ecologically, its copious latex deters herbivory, and it plays a role in early-season pollinator support in montane grassland ecosystems.

Author: Boiss. · Sources: POWO (Kew), GBIF, Flora of China Vol. 11, Annotated Checklist of the Flowering Plants of Nepal

Euphorbiaceae

Euphorbia stracheyi

by G & P Jürgens

Boiss.

Nepal 99 313 ergebnis
West-Nepal Kalmura 4200m, June
Nepal 99 314 ergebnis
West-Nepal Kalmura 4200m, June

Description

Euphorbia stracheyi is a widespread high-altitude spurge of the Himalaya and the Tibetan Plateau, distributed from Nepal, northern India and Bhutan eastward into SW China, with outlying records southeast to Laos and Vietnam. The GBIF dataset, with around 946 occurrences across CN, NP, IN, BT, LA and VN, confirms this broad Sino-Himalayan range. The plant shown was photographed in western Nepal at Kalmura at about 4,200 m in June. It is a true alpine, growing on open stony slopes, gravelly pastures, moraine and turf between roughly 3,000 and 4,800 m, where its prostrate, mat-forming habit suits the cold, exposed and seasonally snow-covered ground.

The species arises from a slender, often elongate creeping rhizome bearing numerous decumbent to ascending reddish stems. The leaves are small, alternate, obovate to oblong and entire. As in all Euphorbia, the inflorescence is a cyathium: the apparent flowers are condensed pseudanthia in which crescent-shaped or transversely elliptic nectar glands surround reduced unisexual flowers, the female reduced to a single stalked tricarpellate ovary and the males to single stamens, the whole subtended by leafy, often reddish-tinged bracts. The fruit is a smooth three-lobed schizocarpic capsule that splits into three mericarps, releasing ovoid seeds; the plant exudes the milky latex typical of the genus.

Euphorbia stracheyi belongs to the subgenus Esula, a group of herbaceous spurges well represented at high elevations across central Asia. Its dwarf, cushion-like form and reddish coloration are adaptations to intense radiation and short growing seasons. The caustic latex deters herbivory and the species is locally common; it is not considered threatened, though like all Euphorbia it falls under CITES listing of the genus for trade-monitoring purposes.

Author: Boiss. · Sources: POWO (Kew), Flora of China Vol. 11, Flora of Bhutan Vol. 1, GBIF, Radcliffe-Smith: Euphorbia in the Flora of Pakistan

Pentaphylacaceae

Eurya acuminata

by GP Jürgens

DC.

Bhutan2012 1009
Bhutan Trithangebe, 1000m October
Bh2008 512 G786
Bhutan Chongsakha, 1850m April

Description

Eurya acuminata is an evergreen shrub or small tree widely distributed through tropical and subtropical Asia, ranging from the Himalaya across southern China, Taiwan and Japan to Indochina, the Malesian archipelago and New Guinea; its roughly 2614 GBIF occurrences span India, Nepal, Bhutan, China, Thailand, Malaysia, Indonesia and the Philippines. In Bhutan it occupies a broad altitudinal range, as recorded at Trithangebe around 1000 m in October and at Chongsakha near 1850 m in April. It grows in evergreen broad-leaved forest, along forest margins and in secondary woodland, often as an understorey or successional component of warm, moist forests.

The plant is a much-branched evergreen with leathery, alternate, distichous leaves that are lanceolate to oblong with the long-acuminate apex recorded in the epithet and a finely serrate margin; the young twigs are often two-edged. The species is dioecious, bearing small, axillary, fragrant flowers that are creamy to greenish-white with five sepals, five petals, and in male plants numerous stamens, while female flowers carry a superior ovary with a short divided style. The fruit is a small, globose, fleshy black berry containing several minute seeds, dispersed by birds.

Eurya, formerly placed in Theaceae and now referred to Pentaphylacaceae, is a large genus of Old World shrubs distinguished by its dioecy, bracteolate flowers and berry fruits; E. acuminata is among the most widespread and variable species, with several recognised varieties. As an abundant, generalist forest component spanning a vast area, it is of least concern, and its dense foliage and wood find local use as fuel, hedging and minor timber.

Author: DC. · Sources: POWO (Kew), GBIF, Flora of China Vol. 12, Flora of Bhutan Vol. 1, Flora of Nepal, Flora Malesiana (Theaceae/Pentaphylacaceae)

Brassicaceae

Eutrema heterophyllum

by G & P Jürgens

(W.W.Sm.) H.Hara

BhutanPG2011 656 ergebnis
Bhutan Thitha-Tso 4360m,July

Description

Eutrema heterophyllum is an alpine crucifer of the high mountains of central Asia and the Himalaya, recorded from China, Nepal, Bhutan, Japan, Tajikistan and Kyrgyzstan, with GBIF logging 226 occurrences. It grows on open alpine slopes, damp gravelly flats, screes and the moist margins of glacial lakes and snowmelt rills. The photographed plant comes from Thitha Tso in Bhutan at about 4360 m, flowering in July, a cold, high-elevation lakeside habitat typical of the species' upper-alpine preference.

It is a small, glabrous perennial or biennial herb arising from a slender rootstock, with one or more ascending stems. As the epithet heterophyllum signals, the foliage is variable: basal leaves are often petiolate and entire to lobed, while the cauline leaves differ in shape and become smaller upward. The flowers are borne in a terminal raceme, small, with four white petals in the cruciferous cross arrangement and six tetradynamous stamens. The fruit is a slender, somewhat flattened silique containing the seeds in a single row.

The taxon is accepted, having been transferred to Eutrema by H. Hara from W.W. Smith's original placement. Eutrema, the genus of wasabi, has been substantially recircumscribed by molecular work that drew in numerous small alpine Sino-Himalayan species formerly scattered among other crucifer genera. As a cold-adapted, broadly distributed high-altitude herb it exemplifies the central-Asian alpine element of the Himalayan flora and is unlikely to be threatened, though dependent on intact periglacial habitats.

Author: (W.W.Sm.) H.Hara · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Al-Shehbaz's systematic studies of Brassicaceae

Brassicaceae

Eutrema himalaicum

by GP Jürgens

Hook.f. & Thomson

Sikkim2011 248
Sikkim Yumthang 3800m, June

Description

Eutrema himalaicum Hook.f. & Thomson is an alpine crucifer of the high Himalaya and adjacent China, recorded from China, India and Bhutan, with around 249 georeferenced occurrences in GBIF (further scattered records reflect cultivation and herbarium holdings). It occupies moist alpine meadows, streamsides, seepage slopes, gravelly flats and rocky places near snowmelt, generally between about 3500 and 4800 m. The photographed plant was found at Yumthang in Sikkim at about 3800 m in June, in the lush, well-watered subalpine to alpine turf that this small herb favours as the snow recedes.

The plant is a slender annual or short-lived perennial with erect or ascending, often glabrous stems arising from a basal rosette. The leaves are simple, the basal ones petiolate with ovate to deltoid or somewhat hastate blades (recalling the form once distinguished as E. deltoideum), the cauline leaves smaller and shortly stalked to subsessile. The flowers are small and borne in terminal racemes; each has four white petals arranged in the cruciform pattern typical of the family, four free sepals and the tetradynamous stamens of the Brassicaceae. The fruit is a slender silique, the seeds in a single row within each locule.

The genus Eutrema, which includes the cultivated wasabi (E. japonicum), has been substantially recircumscribed by molecular studies, absorbing several formerly segregate Himalayan genera; this accounts for the species' nomenclatural history and the alternate epithet seen on the source page. As a snowbed and seepage specialist it is adapted to short, cool growing seasons. The species is fairly widespread within its alpine band and not of conservation concern, though sensitive to habitat disturbance.

Author: Hook.f. & Thomson · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Al-Shehbaz revision of Eutrema and Tribe Eutremeae, Hara Flora of the Eastern Himalaya

Brassicaceae

Eutrema scapiflorum

by GP Jürgens

(Hook.f. & Thomson) Al-Shehbaz, G.Q.Hao & J.Quan Liu

Bh09 144 P255
Bhutan Al-Shehbaz, 4100m June

Description

Eutrema scapiflorum (Hook.f. & Thomson) Al-Shehbaz, G.Q.Hao & J.Quan Liu is a dwarf alpine crucifer of the high Sino-Himalaya, recorded from China, India, Nepal, Bhutan and Myanmar. The species is illustrated from Bhutan at approximately 4100 m, flowering in June, consistent with its occurrence in the upper alpine belt. It inhabits open stony slopes, moraines, fellfield, gravelly flushes and the margins of snow-fed rills, generally between 3800 and 5000 m, where it endures intense insolation, freezing nights and a compressed growing season. With around 630 GBIF records it is a genuinely high-elevation specialist, scarce and patchily distributed across its range.

The plant is a small, glabrous, cushion- to rosette-forming perennial arising from a stout caudex and taproot. The basal leaves are crowded, spathulate to oblong-obovate, entire or obscurely toothed, and rather fleshy. As the epithet scapiflorum implies, the white flowers are borne on short, nearly leafless scapes scarcely exceeding the foliage, each flower with four spreading petals and the typical cruciferous tetradynamous androecium. The fruit is a short, oblong to linear silique or silicle, somewhat flattened, dehiscing to release a few seeds in two rows.

The taxon was long placed in the segregate genus Pegaeophyton (as P. scapiflorum), reflected in its original webpage URL, but molecular phylogenetic analyses have shown Pegaeophyton to be nested within Eutrema, prompting the present transfer. It belongs to the tribe Eutremeae, a predominantly Himalayan and Central Asian lineage of cold-adapted mustards. Its restricted high-alpine niche renders it sensitive to upslope vegetation shifts and the retreat of late-lying snow, though no formal conservation assessment has yet been made.

Author: (Hook.f. & Thomson) Al-Shehbaz, G.Q.Hao & J.Quan Liu · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Al-Shehbaz revisions of Himalayan Brassicaceae

Gentianaceae

Exacum teres

by GP Jürgens

Wall.

Nepal 95 255 P438 ergebnis
Nepal Valley of Buri Gandaki, Kholabensi 2100m October

Description

Exacum teres is a slender annual gentian of the eastern Himalaya and adjacent Indo-Burmese region, documented by GBIF (about 125 occurrences) from India, Nepal, Bangladesh, China, Myanmar and Bhutan. It grows in moist, open habitats of the warm-temperate and subtropical belt, including grassy banks, terraced field margins, forest clearings and damp roadside slopes, typically below the main forest line. The illustrated material was gathered in the valley of the Buri Gandaki at Kholabensi in Nepal at about 2100 m in October, a montane locality near the upper edge of its altitudinal range, which extends from the lowland hills up into the cooler middle hills.

The plant is an erect, glabrous herb with a quadrangular, often narrowly winged stem (the epithet teres referring to its terete-cylindric aspect) that branches above. The leaves are opposite, sessile to subsessile, ovate to lanceolate, entire, and conspicuously three- to five-nerved from the base. The flowers are borne in a lax terminal and axillary cyme; each has a four-lobed calyx with keeled, narrowly winged segments, and a rotate to broadly campanulate corolla that is blue to violet with a deeper throat. The four stamens bear large yellow anthers that open by terminal pores, a diagnostic feature of Exacum. The bilocular ovary matures into a small, septicidal capsule containing numerous minute, reticulate seeds.

Exacum is a palaeotropical genus centred on Sri Lanka, southern India and Madagascar, with E. teres representing the small Himalayan element of the lineage. As a widespread annual of disturbed and semi-natural grassland it is not considered threatened. Its poricidal anthers and blue corollas indicate buzz-pollination by bees, and several relatives are of horticultural interest as the cultivated Persian violets.

Author: Wall. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Klackenberg's monograph of Exacum (Gentianaceae)

Hamamelidaceae

Exbucklandia populnea

by GP Jürgens

(R.Br. ex Griff.) R.W.Br.

Bh09 232 P388
Bhutan Wangdi, 1700m June

Description

Exbucklandia populnea is an evergreen tree of the family Hamamelidaceae, distributed through the eastern Himalaya and into Southeast Asia. GBIF records document its presence in China, India, Bhutan, Nepal, Myanmar, Thailand, Laos, Vietnam, Malaysia, Indonesia and Sri Lanka, defining a broad Sino-Himalayan to Indo-Malayan range. It is a tree of moist, montane evergreen broad-leaved forest, often locally dominant in mid-elevation forest and on ridge crests, typically between about 1,000 and 2,500 m. The individual illustrated near Wangdue Phodrang (Wangdi) in Bhutan at around 1,700 m in June is characteristic of this humid mid-montane forest belt.

The species is a tall tree reaching 20–30 m with a straight bole and smooth grey bark. The leaves are alternate, long-petiolate, with broadly ovate, palmately three- to five-veined, often shallowly lobed blades reminiscent of a poplar, hence the epithet populnea; they are leathery and glabrous, with the petiole bearing conspicuous, large, paired stipules that sheath the bud and leave an annular scar on falling. The flowers are small, apetalous and aggregated into dense, rounded, capitate heads, the heads themselves grouped on a common axis; each head bears stamens and bicarpellate ovaries. The fruit is a woody capsule, several aggregated into a globose head, dehiscing to release small winged seeds.

The genus Exbucklandia is an isolated member of the relictual, largely Asian family Hamamelidaceae, a group of considerable phylogenetic interest in understanding early angiosperm woody lineages. The conspicuous stipules and capitate, apetalous inflorescences are diagnostic. The timber is locally used in construction and the species is an important canopy component of eastern Himalayan evergreen forest. Though widely distributed and not globally threatened, its montane forest habitat is locally subject to logging and conversion.

Author: (R.Br. ex Griff.) R.W.Br. · Sources: POWO (Kew), GBIF, Flora of China Vol. 9, Flora of Bhutan Vol. 1, Flora of Nepal, Endress: Hamamelidaceae and adjacent families

Polygonaceae

Fagopyrum esculentum

by GP Jürgens

Moench

Bhutan2012 155
Bhutan Haar-Valley, 3100m September

Description

Fagopyrum esculentum, common buckwheat, is a domesticated annual of South-East Asian and Sino-Himalayan origin now cultivated and naturalised across the temperate world, accounting for its more than 72,000 GBIF occurrences in France, the Netherlands, Germany, Russia, China, Korea, Japan, the United States and Canada among many others. In the Himalaya it is a traditional mountain crop grown on terraced fields and as an escape on disturbed ground at middle to high elevations. The record from the Haa Valley of western Bhutan at 3100 m in September captures it in flower and early fruit at the close of a typical subalpine growing season.

It is an erect, glabrous annual 30-90 cm tall with reddish, somewhat fleshy stems and characteristic membranous ochreae sheathing the nodes. The leaves are alternate, broadly triangular-cordate to hastate, the lower ones petiolate and the upper sessile and clasping. The flowers are small, borne in dense axillary and terminal corymbose racemes, with a five-parted white to pinkish perianth, eight nectary-bearing stamens and a tristylous heterostylous breeding system promoting outcrossing. The fruit is a sharply three-angled, smooth brown achene (the buckwheat "grain") much exceeding the persistent perianth.

Within Polygonaceae the genus Fagopyrum is distinguished by its trigonous achenes and heterostyly; F. esculentum is the principal cultivated species, complemented by Tartary buckwheat F. tataricum. It is insect-pollinated, valued as a nectar source and pseudocereal, and is of agricultural rather than conservation interest, persisting widely as a weedy escape from cultivation.

Author: Moench · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora Europaea, Ohnishi monograph of Fagopyrum