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.

Orchideaceae

Pleione praecox

by G & P Jürgens

(Sm.) D.Don

Bhutan2012 828 Kopie
Bhutan Tongsa 2050m, October
Bhutan2012 831 Kopie
Bhutan Tongsa 2050m, October
Bhutan2012 1302
Bhutan Trashigang 1900m, October

Description

Pleione praecox is an autumn-flowering epiphytic and lithophytic orchid of the eastern Himalaya and Indo-Burmese region, ranging through India, Nepal, Bhutan, China, Thailand, Myanmar, Vietnam and Bangladesh, with cultivated records in Britain and the United States among its roughly 335 GBIF occurrences. It grows on mossy tree trunks, rocks and banks in humid broadleaved montane forest, typically between about 1200 and 2500 m. The cited Bhutanese plants from Trongsa (2050 m) and Trashigang (1900 m), both flowering in October, exemplify its diagnostic late-season anthesis, the epithet praecox referring to bloom appearing as or before the leaves develop.

The species is a deciduous sympodial orchid producing conspicuous, flask-shaped to conical pseudobulbs, often mottled green and purple, each typically bearing one or two pleated, lanceolate leaves that are shed in the dormant season. The showy flowers, borne singly (rarely paired) on a short scape from the base of a pseudobulb, have spreading rose-pink to magenta sepals and petals. The funnel-shaped labellum is the showpiece: broad, fimbriate at the margin, and marked internally with several toothed or lamellate crests and reddish-brown blotching. The column is slender and winged, and the fruit is an ellipsoid capsule.

Pleione is a small genus of subtribe Coelogyninae, and P. praecox is among its most horticulturally prized species, widely cultivated by alpine and orchid growers, which accounts for its scattered records in Europe and North America. Its showy labellum attracts bee pollinators despite offering little reward. Although locally frequent, wild populations face pressure from commercial and amateur collection of pseudobulbs and from clearance of montane forest, making in-situ conservation of its epiphytic habitat important.

Author: (Sm.) D.Don · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China (Orchidaceae), Cribb & Butterfield The Genus Pleione

Podocarpaceae

Podocarpus neriifolius

by G & P Jürgens

D.Don

Bhutan2015 187
Bhutan Zhemgang 1000m, October
Bhutan2015 188
Bhutan Zhemgang 1000m, October
Bhutan2014 194
Bhutan Trashyangtse 2100m, May
Bhutan2014 195
Bhutan Trashyangtse 2100m, May

Description

Podocarpus neriifolius, the brown pine or oleander-leaved podocarp, is a broadly distributed evergreen conifer of tropical and subtropical Asia and the western Pacific, with GBIF recording over 3,100 occurrences from Papua New Guinea, Fiji, Indonesia, Vietnam, China, Malaysia, the Solomon Islands, the Philippines, India, Thailand, Nepal, Vanuatu, Cambodia, Laos and beyond. In the eastern Himalaya it occurs in warm broad-leaved and mixed forest of the foothills and lower mountains, generally between about 500 and 2100 m. The images from Zhemgang in Bhutan at 1000 m, in October, and from Trashyangtse at 2100 m, in May, bracket its altitudinal range in that country, showing it as a scattered emergent or canopy tree in humid, evergreen subtropical forest on well-drained slopes.

It is an evergreen tree commonly 10-25 m tall, occasionally much larger, with grey to brown, fibrous, flaking bark and a dense crown. The leaves are spirally arranged but often appearing two-ranked, simple, narrowly lanceolate and leathery with a prominent midrib and a long, gradually tapering apex, recalling the foliage of oleander as the epithet indicates. The species is dioecious: pollen cones are slender, cylindrical and borne in leaf axils, while the seed cones are reduced to one or two ovules seated on a swollen, fleshy receptacle (the epimatium and aril) that ripens red to purple, the single seed crowned by a green to bluish covering and dispersed by birds.

Podocarpus is the largest genus of the Southern Hemisphere-centred family Podocarpaceae, and P. neriifolius is among its most wide-ranging species, exhibiting considerable variation in leaf size across its vast area. It is valued for its fine, even timber, which has led to local overexploitation, though its enormous geographic range means it is assessed by the IUCN as Least Concern overall. In the Himalaya it represents a tropical-Gondwanan conifer lineage reaching its northern limits in the warm forests of the eastern foothills.

Author: D.Don · Sources: POWO (Kew), GBIF, Flora of China Vol. 4, Flora of Bhutan Vol. 1, Flora of Nepal, de Laubenfels' revision of Podocarpus and the Podocarpaceae

Berberidaceae

Podophyllum aurantiocaule

by G & P Jürgens

Hand.-Mazz.

BhutanPG2011 57JPG
Bhutan Jakar 2600m June
Bh09 295 G486
Bhutan Pele-La, 3200m June
Bh09 296 G487
Bhutan Pele-La, 3200m June

Description

Podophyllum aurantiocaule is a Sino-Himalayan woodland herb recorded from China, Myanmar and India (with one extralimital cultivated record from the Netherlands), the c. 25 georeferenced occurrences reflecting a relatively narrow and uncommon distribution in the eastern Himalaya and adjacent mountains. It grows in the shade and humus of temperate broadleaved and conifer forest, on cool, moist, sheltered slopes and forest floor, generally between about 2400 and 3400 m. The illustrated plants were photographed at Jakar in Bhutan at 2600 m and at Pele-La at 3200 m, both in June, sites characteristic of the species, which emerges and flowers in early summer beneath the forest canopy. Under GBIF this name is treated as a synonym, with Podophyllum aurantiocaule itself recognised as the accepted name in that backbone.

It is a perennial herb arising from a stout creeping rhizome, sending up an erect, fleshy, often orange-tinted stem, the colouration reflected in the epithet aurantiocaule. The stem bears typically two large, long-petioled, peltate to deeply palmately lobed leaves whose margins are toothed. A single, rather large, nodding flower is borne at the fork between the leaves; it has free, somewhat fleshy petals in shades of dull red to purplish, numerous stamens and a single superior carpel. The fruit is a large fleshy berry containing many seeds embedded in pulp.

The Asian podophylloids, treated either in a broad Podophyllum or in the segregate genera Dysosma and Sinopodophyllum, are placed in Berberidaceae and are renowned for the lignan podophyllotoxin, precursor of the anticancer drugs etoposide and teniposide. As a slow-growing, rhizomatous, narrowly distributed forest herb subject to medicinal collection and habitat loss, P. aurantiocaule is intrinsically vulnerable, and members of this complex are widely flagged for conservation attention.

Author: Hand.-Mazz. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Shaw monograph of the podophylloid Berberidaceae

Berberidaceae

Podophyllum hexandrum

by GP Jürgens

Royle

Sikkim2011 57
Sikkim Tanghu 3900m, June
Sikkim2011 70
Sikkim Tanghu 3900m, June
Sikkim2011 72
Sikkim Tanghu 3900m, June

Description

Podophyllum hexandrum, the Himalayan mayapple, is a perennial herb of the high temperate and subalpine Himalaya, occurring through China, India, Pakistan, Nepal, Bhutan and Afghanistan, with around 860 occurrences in GBIF. It grows in moist alpine meadows, open fir and birch forest, shaded scrub and along the margins of melting snowfields, typically between about 2500 and 4500 m. The plant photographed at Tanghu in northern Sikkim at 3900 m in June, emerging and flowering as the snow recedes, is characteristic of its high-elevation niche, where the rich, moist humus of the upper forest and meadow ecotone supports dense local stands.

The species arises from a stout, creeping, knotty rhizome and produces a single erect aerial stem 15–50 cm tall bearing usually two large, long-petiolate leaves that are deeply palmately three- to five-lobed, the lobes themselves further cut and toothed, often bronze-mottled when young. A solitary, nodding to erect flower is borne at the fork of the leaves; it is cup-shaped with white to pale pink petals and (as the epithet indicates) commonly six stamens. The fruit is a large, fleshy, ovoid berry ripening to bright red and containing numerous seeds embedded in pulp.

GBIF flags the name as a synonym, the species being widely treated under the accepted name Podophyllum hexandrum, with the genus Sinopodophyllum (S. hexandrum) recognised by some authors to accommodate the Asian taxon apart from the North American Podophyllum peltatum; the source page links to that segregate name. The plant is the principal natural source of podophyllotoxin, a lignan of major pharmaceutical importance as a precursor of anticancer agents. Heavy harvesting of the rhizomes for this trade, together with habitat disturbance, has caused marked local declines, and the species is regarded as threatened and is subject to conservation and CITES-related concern across much of its range.

Author: Royle · Sources: POWO (Kew), GBIF, Flora of China Vol. 19, Flora of Bhutan Vol. 1, Flora of Pakistan, Medicinal Plants of the Himalaya: A Monograph of Podophyllum

Lamiaceae

Pogostemon linearis

by GP Jürgens

Kuntze

Bhutan2012 1165
Bhutan Trashiyangtse 1780m, October

Description

Pogostemon linearis is an Asian mint distributed through India, China, Bhutan, Myanmar, Bangladesh and westward to Iran, with around 99 georeferenced records in GBIF. It is a plant of warm-temperate to subtropical hill country, occurring on open grassy slopes, forest edges, streambanks and disturbed ground in the lower and middle montane zone. The Bhutanese material photographed near Trashiyangtse at about 1780 m in October reflects its typical autumn flowering at modest elevation, where it benefits from the warm, moist conditions of the eastern Himalayan foothills and frequently colonises seasonally damp, sunny situations.

The species is an erect to ascending herb or subshrub with quadrangular stems that are often pubescent. The leaves, as the epithet indicates, are narrow, linear to linear-lanceolate, sessile or shortly petiolate, with serrate to subentire margins and an acute apex. The flowers are borne in dense, cylindrical, spike-like verticillasters forming a terminal thyrse; each small flower has a tubular, five-toothed calyx and a campanulate, weakly two-lipped corolla. The four stamens are characteristically long-exserted and bear conspicuously bearded filaments, a diagnostic feature of Pogostemon, giving the inflorescence a fluffy appearance. The fruit comprises four smooth nutlets enclosed by the persistent calyx.

Described by Kuntze, P. linearis belongs to a genus best known for P. cablin, the source of patchouli oil. The bearded, far-exserted stamens place it firmly within Pogostemon and distinguish it from related Lamiaceae genera. Its broad distribution, ecological tolerance and association with open and disturbed habitats indicate a secure conservation status throughout its range.

Author: Kuntze · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Bhatti & Ingrouille revision of Pogostemon

Polemoniaceae

Polemonium caeruleum var. himalayanum

by G & P Jürgens

Baker

Nepal 99 85 ergebnis
West-Nepal Bhulbhule 3200m, June
Garh 07 573 ergebnis
Garh 07 574 ergebnis
India Garhwal Seema 3400m, June

Description

Polemonium caeruleum var. himalayanum is the Himalayan expression of the wide-ranging Jacob's ladder, here documented chiefly from Nepal, with only about 16 georeferenced GBIF occurrences reflecting its restricted recording rather than true rarity. It is a herb of moist alpine and upper-subalpine meadows, streambanks, open shrubberies and damp rocky slopes, typically between about 3000 and 4000 m. The populations noted at Bhulbhule in West Nepal at 3200 m and at Seema in Garhwal at 3400 m, both flowering in June at the start of the monsoon, are characteristic of its preference for cool, humus-rich, seasonally moist ground in the high western and central Himalaya.

It is an erect perennial herb arising from a short rhizome, the stems leafy and often glandular-pubescent above. The leaves are alternate and pinnately compound, the numerous lanceolate to ovate leaflets arranged ladder-like along the rachis, giving the plant its vernacular name. The flowers are borne in a terminal, somewhat congested panicle; each has a campanulate, glandular five-lobed calyx and a broadly campanulate to rotate blue corolla with five spreading lobes, the five stamens inserted in the throat with hairy filament bases, and a three-lobed style exserted. The fruit is an ovoid, three-valved loculicidal capsule containing several angular seeds.

GBIF treats the name as a synonym, with Polemonium caeruleum himalayanum recognised as the accepted infraspecific taxon within the circumboreal P. caeruleum complex. The protandrous, nectar-rich flowers are visited by bees and long-tongued insects, promoting outcrossing. As a high-altitude meadow plant it is sensitive to overgrazing, though not presently assessed as threatened.

Author: Baker · Sources: POWO (Kew), GBIF, Flora of Nepal, Flora of Bhutan Vol. 2, Flora of China Vol. 16, A Systematic Treatment of Polemonium (Polemoniaceae)

Polygalaceae

Polygala arillata

by GP Jürgens

Buch.-Ham. ex D. Don

Bhutan2014 669
Bhutan Wangdi-Phodrang 2280, May

Description

Polygala arillata is a shrubby milkwort of the Himalaya and Southeast Asia, distributed from Nepal, NE India and Bhutan through southern China to Myanmar, Thailand, Vietnam, Bangladesh, Sri Lanka and Malesia, with 2,908 GBIF occurrences. It grows in temperate and subtropical broad-leaved forest, forest margins, clearings and shrubby slopes, commonly between about 1,000 and 2,800 m. The Bhutanese collection from Wangdi Phodrang at about 2,280 m in May reflects its late-spring flowering in mid-montane forest, where it grows as a conspicuous understorey or edge shrub.

It is an erect shrub or small tree 1–3 m tall with terete, finely pubescent branchlets. The leaves are alternate, elliptic to obovate-oblong, 8–18 cm long, acuminate, entire and shortly petiolate, often somewhat membranous. The inflorescence is a pendent terminal or leaf-opposed raceme of showy flowers; each flower has five sepals, the two inner enlarged into petaloid, deep yellow to reddish wings, and three petals fused into a tube with a fringed keel, the whole strongly zygomorphic. The fruit is a fleshy, laterally compressed, reddish capsule, and the seeds bear a conspicuous white aril, from which the epithet arillata is derived.

The species belongs to the large, cosmopolitan genus Polygala and is among its more robust, woody Asian representatives. GBIF treats the name as accepted. The arillate seeds suggest dispersal by birds or ants attracted to the fleshy appendage, and the showy keeled flowers are adapted to insect pollination. Widespread and locally common, it is of least concern; its roots and bark are used in regional traditional medicine.

Author: Buch.-Ham. ex D. Don · Sources: POWO (Kew), Flora of China Vol. 11, Flora of Bhutan Vol. 1, GBIF, Bennett: Polygalaceae in Hooker's Flora of British India (1882)

Polygalaceae

Polygala sibirica

by GP Jürgens

L.

Bh2008 521 G796
Bhutan Punakha 2400m, May

Description

Polygala sibirica L. is a small perennial milkwort with one of the widest distributions in its genus, ranging across temperate Eurasia from eastern Europe through Central and northern Asia to the Himalaya, China, Japan and southward into Southeast Asia and Australasia. GBIF records confirm its presence in Russia, China, Mongolia, India, Nepal, Bhutan, Pakistan, Korea, Japan and many other countries, with several thousand occurrences. It grows on dry grassy slopes, open stony banks and forest margins from the lowlands to about 3,000 m. The plant photographed at Punakha in Bhutan at 2,400 m, flowering in May, exemplifies its occurrence on sunny montane slopes.

The species is a tufted perennial herb arising from a woody rootstock, with several ascending to spreading, often hairy stems 10–30 cm long. The leaves are alternate, sessile or nearly so, lanceolate to elliptic, the lower ones smaller. The flowers are borne in lax terminal racemes; the two large petaloid lateral sepals (wings) are greenish-veined, and the small blue to purplish corolla bears a conspicuous fringed keel-petal crest. The fruit is a flattened, narrowly winged, obcordate capsule containing two hairy seeds with a small aril.

Polygala sibirica is closely allied to the medicinally important P. tenuifolia, and its roots are similarly used in traditional Chinese medicine (yuan zhi) as a source of saponins. Its enormous range and ecological tolerance make it one of the most successful milkworts, and it is of least conservation concern.

Author: L. · Sources: POWO (Kew), GBIF, Flora of China Vol. 11, Flora of Bhutan Vol. 1, Bennett: Polygalaceae in Hooker's Flora of British India

Asparagaceae

Polygonatum brevistylum

by G & P Jürgens

Baker

Sikkim 2006 315 ergebnis
India West-Bengal, Chaana 1800m, May

Description

Polygonatum brevistylum is a rhizomatous perennial of the eastern Himalaya and adjacent ranges. GBIF documents it (some 27 occurrences) from Nepal, India, Bhutan and Myanmar, in moist temperate forest, forest margins, shrubberies and shaded banks. It grows in cool, humus-rich soils within the broadleaved and mixed conifer zone, generally between about 1,500 and 3,000 m. The photographed plant is from Chaana in West Bengal (Darjeeling–Sikkim Himalaya) at around 1,800 m, flowering in May, a representative low-montane station for the species as it sends up shoots in spring.

The plant has a stout, knotty, horizontally creeping rhizome from which arises an erect or arching stem. The leaves are alternate, ovate to elliptic and acuminate, glabrous, sessile or shortly petiolate. The flowers are pendent and borne in few-flowered axillary clusters; the perianth is tubular-campanulate, white to greenish-white, with six short lobes, and, as the epithet brevistylum signals, a notably short style. The fruit is a globose berry, ripening blue-black to purplish and containing several seeds.

Polygonatum (Solomon's-seal), now placed in Asparagaceae (formerly Convallariaceae or Liliaceae sensu lato), is taxonomically intricate in the Himalaya, where several closely allied rhizomatous species occur. The short style and the clustered axillary flowers are useful diagnostic characters separating P. brevistylum from sympatric congeners. Himalayan Polygonatum rhizomes are widely gathered for food and traditional medicine, so localised harvesting pressure may affect accessible populations.

Author: Baker · Sources: POWO (Kew), Flora of China Vol. 24, Flora of Bhutan Vol. 3, GBIF, Jeffrey: The Genus Polygonatum (Liliaceae) in Eastern Asia

Asparagaceae

Polygonatum cirrhifolium

by GP Jürgens

(Wall.) Royle

Bh2008 611 P920
Bhutan, Punakha 2400m, May

Description

Polygonatum cirrhifolium is a rhizomatous perennial herb widely distributed across the Himalaya and the mountains of central and western China, recorded from China, Nepal, India, Bhutan, Myanmar and Vietnam, with around 2251 georeferenced records (records from Canada, Norway and Britain reflect cultivation). It occurs in temperate forest, forest margins, shrubberies and grassy alpine slopes, on moist humus-rich soils typically between about 2000 and 4000 m. The photographed plant from Punakha in Bhutan at 2400 m, flowering in May, sits near the lower edge of its broad altitudinal span.

It has a stout, knotted, horizontal rhizome from which arises an erect to arching stem. The narrow, linear-lanceolate leaves are borne in whorls of three or more, and the epithet cirrhifolium refers to their slender apices, which are characteristically prolonged and curled into tendril-like tips. The pendent flowers hang one to four together in the leaf axils; each perianth is tubular, pale rose-purple to whitish, the six tepals fused into a cylinder with short lobes and enclosing six stamens. The fruit is a globose berry that ripens from red to purplish-black.

Polygonatum, in Asparagaceae subfamily Nolinoideae, is here represented by a whorled-leaved species readily told from P. oppositifolium by its tendrilled leaf tips. The rhizome, known in Chinese and Himalayan medicine, is gathered as a tonic drug, and the species is among the sources of the herbal material huangjing. The pendent nectar-bearing flowers are bumblebee-pollinated and the berries bird-dispersed. Though widespread and not threatened overall, sustained medicinal harvesting locally depletes wild populations.

Author: (Wall.) Royle · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Jeffrey monograph of Polygonatum