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.

Urticaceae

Pilea insolens

by G & P Jürgens

Wedd.

Sikkim2011 6
Bhutan Tista-valley 1900m, October

Description

Pilea insolens is a Sino-Himalayan herbaceous species distributed from central Nepal through Sikkim, Bhutan, and northeast India (Darjeeling, Arunachal Pradesh) to Bangladesh, Myanmar, southern China, Japan, and Indonesia. GBIF records 94 occurrences across this range. The species inhabits damp, shaded habitats in subtropical and warm-temperate forests at elevations of 800–2,400 m, where it colonises moist rocks, stream banks, tree bases, and old walls in areas of high humidity. It is most abundant in the eastern Himalayan valleys that receive heavy monsoon precipitation.
Pilea insolens is a succulent, erect to ascending, monoecious perennial herb, 15–40 cm tall. Stems are fleshy, translucent, glabrous, and often reddish-brown at the base. Leaves are opposite, markedly anisophyllous — a characteristic feature, with the larger leaf of each pair broadly ovate to suborbicular, 3–8 cm long, and the smaller leaf often reduced to a stipule-like scale or small blade less than 1 cm. The larger leaf surface is dark green, often with a cystolith-dotted texture visible as pale streaks, with crenate to serrate margins and three prominent basal veins. Stipules are small, membranous, and soon deciduous. Male and female flowers are borne in separate axillary cymes on the same plant; the male flowers are minute with four perianth segments, while the female flowers are even smaller, with an achene enclosed by persistent perianth lobes.
The photographed specimen from the Tista valley in Bhutan at 1,900 m in October represents a typical occurrence in the humid, deeply incised river valleys of the eastern Himalayas. Pilea insolens is distinguished from other Himalayan congeners by its pronounced leaf anisophylly combined with the broadly ovate, crenate larger leaf. The genus Pilea is enormous, with over 700 species globally, and the eastern Himalayan region is a centre of diversity with numerous narrowly distributed endemics. The species' extension from the Himalayas into Japan and Indonesia reflects a shared subtropical element across the monsoon-influenced forests of East and Southeast Asia. Its reliance on humid, undisturbed forest microsites makes it sensitive to deforestation and stream-channel modification.

Author: Wedd. · Sources: POWO (Kew), GBIF, Flora of China Vol. 5, Flora of Bhutan Vol. 1, Grierson & Long (1983), Chen (1982) — Revision of Chinese Pilea

Urticaceae

Pilea symmeria

by G & P Jürgens

Wedd.

Bhutan2014 833
Bhutan Thimphu 2450m, May

Description

Pilea symmeria is a herbaceous member of the nettle family with a broad Asian range, GBIF documenting it from China, Nepal, Bhutan, NE India, Thailand, Indonesia and Japan across some 217 records. It is a plant of shaded, humid habitats, growing on moist rock faces, stream banks, ravines and the floor of broadleaved evergreen forest. The photographed plant from Thimphu in Bhutan at 2,450 m (May) is representative of its mid-montane occurrence, where it favours cool, sheltered and consistently damp microsites typical of the genus.

It is a soft, glabrous perennial or annual herb with succulent, often translucent stems frequently rooting at the lower nodes. The leaves are opposite, equal or somewhat unequal in a pair, ovate to elliptic, with a toothed or crenate margin and conspicuous linear cystoliths visible on the surface, the venation triplinerved at the base as is characteristic of Pilea. The plants are typically monoecious, the minute unisexual flowers borne in small axillary cymes; the male flowers have a 4-merous perianth and explosively dehiscent stamens, while the female flowers produce a small, compressed achene.

The family is here correctly Urticaceae. Pilea is the largest genus of the nettle family and a notoriously difficult one, the species separated on subtle differences in leaf shape, stipules, cystolith pattern and inflorescence. The explosive release of pollen by the recoiling stamens is a hallmark dispersal mechanism of the family. As a widespread, shade-adapted forest herb of no particular rarity, P. symmeria is not regarded as threatened, though it is sensitive to disturbance of the humid forest understorey it requires.

Author: Wedd. · Sources: POWO (Kew), Flora of Bhutan Vol. 1, GBIF, Flora of China Vol. 5, Friis: Urticaceae (in Families and Genera of Vascular Plants)

Urticaceae

Pilea umbrosa 

by G & P Jürgens

Wedd. ex. Blume

Garw 2005 220 ergebnis ergebnis
India Garhwal Simkarok 2700m, September

Description

Pilea umbrosa is a shade-loving herb of moist montane forests across the Himalaya and into south-east Asia, recorded from Nepal, India, China, Pakistan, Bhutan and Vietnam. The roughly 307 georeferenced collections trace the temperate forest belt from the western Himalaya eastward. As its epithet (umbrosa, "of shady places") implies, it occupies damp, humus-rich, deeply shaded sites: forest floors, rock crevices, mossy banks and the margins of streams beneath broadleaved and mixed canopy. The photographed material from Garhwal at Simkarok at 2700 m in September is characteristic of its upper-temperate habitat and its late-monsoon fruiting period.

It is a succulent, often fleshy perennial herb with semi-translucent, somewhat brittle stems that may root at the lower nodes. The opposite leaves are markedly anisophyllous, the two of a pair unequal in size, ovate to elliptic, with a toothed (serrate to crenate) margin and a characteristic triple primary venation; linear cystoliths are visible on the surface, a diagnostic feature of the genus. Stipules are present at the nodes. As in most Urticaceae the inflorescences are small, axillary cymes of inconspicuous, unisexual, greenish flowers, the male flowers with reflexed tepals and explosively dehiscent stamens that fling pollen at maturity. The fruit is a minute, compressed achene.

Pilea is one of the largest genera of Urticaceae, predominantly tropical and subtropical, and unusually for the family it lacks stinging hairs, making it harmless to handle. The explosive stamen mechanism enabling wind dispersal of pollen is a hallmark of the family. P. umbrosa is a widespread, locally abundant understorey element with no conservation concern, valued ecologically as ground cover that stabilises soil on shaded forest slopes.

Author: Wedd. ex. Blume · Sources: POWO (Kew), GBIF, Flora of China Vol. 5, Flora of Bhutan Vol. 1, Flora of Pakistan, Friis's Revision of Asian Urticaceae

Orchideaceae

Pinalia acervata

by GP Jürgens

(Lindl.) Kuntze

Bhutan2012 1144
Bhutan, Trashiyangtse 1780m, October
Bhutan2012 1143
Bhutan, Trashiyangtse 1780m, October

Description

Pinalia acervata is an epiphytic orchid of the warm-temperate and subtropical forests of tropical Asia, ranging widely from China and India through Myanmar, Thailand, Vietnam, Cambodia, Malaysia and Singapore to Bhutan and Nepal, with 114 GBIF records reflecting this broad Indo-Burmese and Sino-Himalayan span. It grows as a humidity-loving epiphyte on mossy trunks and branches in evergreen broadleaved forest, generally at low to moderate elevations. The illustrated plant was found at Trashiyangtse in eastern Bhutan at about 1780 m in October, in the warm, monsoon-fed valleys where epiphytic orchid communities are particularly rich.

The species forms clustered, cylindrical to fusiform pseudobulbs that are densely tufted, each bearing several distichous, lanceolate to oblong leaves toward the apex. The inflorescences are lateral racemes, frequently densely many-flowered and clothed, like the ovaries and outer floral parts, in the rusty or whitish woolly indumentum characteristic of the segregate genus. The small flowers are whitish to pale yellow, with a saccate mentum formed by the lateral sepals against the column foot, and a small three-lobed lip; the fruit is a small ribbed capsule.

The taxon was long placed in the large pantropical genus Eria, as Eria acervata, and the basionym (Lindl.) Kuntze reflects this history; modern phylogenetic work has resolved many former Eria species into smaller, better-circumscribed genera, with this species now treated under Pinalia in tribe Podochileae. As a widespread, adaptable epiphyte it is not considered threatened, though local populations depend on the persistence of humid forest canopy and are diminished by deforestation.

Author: (Lindl.) Kuntze · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Genera Orchidacearum (Pridgeon et al.)

Orchideaceae

Pinalia amica

by GP Jürgens

(Rchb.f.) Kuntze

Bh2008 320 P495
Bhutan Jakar, 2950m April
Bh2008 321 G496
Bhutan Jakar, 2950m April

Description

Pinalia amica (Rchb.f.) Kuntze, long known under Eria amica, is an epiphytic orchid widely distributed through tropical and subtropical Asia. GBIF records (about 203 occurrences) extend from Nepal, northern India and Bhutan eastward through Myanmar, southern China, Taiwan, Thailand, Laos, Cambodia, Vietnam and Malaysia. It grows as an epiphyte, occasionally a lithophyte, on mossy trunks and branches in humid broad-leaved and mixed forest, from the foothills up to about 2000-3000 m. The plant photographed at Jakar in Bhutan at 2950 m in April, flowering in spring, occurs near the upper part of its altitudinal range in cool, moist montane forest where high humidity and shaded, well-aerated bark provide its rooting substrate.

It is a sympodial epiphyte with cylindric to fusiform pseudobulbs or stems clustered on a creeping rhizome, each bearing a few apical leaves. The leaves are oblong-lanceolate, leathery and several-nerved. The inflorescence is a lateral raceme of several to many flowers, the rachis and ovaries usually finely hairy. The flowers are small, cream to pale yellow, often marked with reddish-brown striations; the sepals form a short mentum at the base with the column foot, and the lip is three-lobed and bears longitudinal keels or calli. The pollinarium carries eight waxy pollinia, and the fruit is a ribbed dehiscent capsule releasing dust-like seeds.

The broadly circumscribed genus Eria has been dismembered on molecular evidence, and species of the Eria amica group are now placed in Pinalia within tribe Podochileae; Pinalia amica is the currently accepted name. Like most epiphytic orchids it depends on mycorrhizal fungi for seed germination and produces enormous numbers of minute wind-dispersed seeds. Widespread across Asia, it is not regarded as threatened overall, though, as with all orchids, it is listed on CITES Appendix II, and local populations are sensitive to deforestation and collection.

Author: (Rchb.f.) Kuntze · Sources: POWO (Kew), GBIF, Flora of China, The Orchids of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Ng et al. molecular phylogeny of Eria and allied genera

Orchideaceae

Pinalia excavata

by GP Jürgens

(Lindl.) Kuntze

Bhutan2014 177
Bhutan Trashigang 2100m, May

Description

Pinalia excavata is an epiphytic orchid of the Eastern Himalaya and adjacent southern China and Indochina, with GBIF records from China, India, Nepal, Bhutan and Myanmar and a modest tally of documented occurrences. It grows as an epiphyte on tree trunks and mossy branches in humid broad-leaved and evergreen montane forest, favouring shaded, well-ventilated situations in the warm-temperate to lower montane belt. The species occupies low to middle elevations; the photographed plant from Trashigang in eastern Bhutan at about 2100 m in May represents a typical station within its altitudinal range, flowering in late spring as the pre-monsoon humidity rises.

The plant produces clustered, fusiform to cylindrical pseudobulbs arising from a creeping rhizome, each bearing several apical leaves. The leaves are lanceolate to elliptic, thin-textured to somewhat leathery and prominently veined. The inflorescence is a lateral or subterminal raceme bearing numerous small flowers, the rachis and ovaries usually clothed in fine hairs as is characteristic of the genus. The flowers are pale, whitish to cream or yellowish, with spreading sepals and petals; the lateral sepals are adnate to the column foot to form a short mentum, and the trilobed labellum bears raised keels or ridges along its disc. The column is short and footed, and the fruit is a small ribbed capsule.

Pinalia comprises species formerly placed in the broadly circumscribed Eria, segregated on the basis of molecular and morphological evidence; P. excavata was originally described under Eria and is treated by current authorities under Pinalia. As a forest epiphyte dependent on intact humid canopy, it is vulnerable to deforestation and habitat degradation across its range, although it is not presently the subject of a formal threat assessment.

Author: (Lindl.) Kuntze · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, The Orchids of Bhutan (Pearce & Cribb)

Orchideaceae

Pinalia leucantha

by GP Jürgens

Kuntze

Nepal 2001 462 ergebnis ergebnis
Nepal (Gorkha) Gunda 1700m, May

Description

Pinalia leucantha is an epiphytic orchid of the central and eastern Himalaya, recorded from northern India, Nepal, Bhutan and adjacent southern China, with georeferenced collections (c. 59 in GBIF) along the moist subtropical to lower temperate belt of the range. It typically grows on mossy trunks and major branches of broad-leaved forest trees, occasionally on shaded rocks, between roughly 1000 and 2000 m. The photographed plant from Gorkha district, Gunda (1700 m, flowering in May), is characteristic of this monsoon-influenced habitat, where high humidity and a marked dry winter govern the growth cycle.

The species is a tufted, sympodial epiphyte forming clustered, fusiform to cylindrical pseudobulbs that are several-noded and clothed when young in papery sheaths. Each pseudobulb bears a few apical, oblong-lanceolate to elliptic, coriaceous leaves with acute tips. The inflorescence is a lateral to subterminal raceme carrying numerous small, whitish to cream flowers, the floral parts frequently invested with fine ferruginous hairs typical of the genus. Sepals and petals are spreading, the lateral sepals adnate to the column foot to form a short mentum; the lip is three-lobed with a fleshy, often keeled disc, and the pollinia are eight, waxy and clavate.

The genus Pinalia comprises species formerly placed in a broadly circumscribed Eria, segregated within tribe Podochileae (subtribe Eriinae) on vegetative and column characters supported by molecular data, and many Himalayan epiphytes have been recombined into it. As a widespread forest epiphyte, P. leucantha is not currently regarded as threatened, though like most epiphytic orchids it is sensitive to deforestation and collection; CITES Appendix II listing applies to all Orchidaceae in trade.

Author: Kuntze · Sources: POWO (Kew), GBIF, Flora of Nepal, Flora of Bhutan, Flora of China (Orchidaceae), The Orchids of Bhutan

Pinaceae

Pinus bhutanica

by G & P Jürgens

Grierson, D.G.Long & C.N.Page

Bhutan2015 468
  Bhutan Trongsa 2300m, October
Bh2008 479 P744
Bhutan, Chongsakha 1800m, May

Description

Pinus bhutanica Grierson, D.G.Long & C.N.Page is a five-needled white pine of the eastern Himalaya, restricted to Bhutan, north-eastern India (Arunachal Pradesh) and adjacent south-eastern Tibet (China); GBIF records about 96 occurrences, the few extralimital points reflecting cultivation or database artefacts. It grows in warm-temperate to subtropical montane forest, often on humid, monsoon-exposed slopes, typically between about 1,700 and 2,400 m. Both photographed stands are Bhutanese – Trongsa at 2,300 m in October and Chongsakha at 1,800 m in May – matching its known occurrence in the wet central and eastern Bhutanese hills.

It is an evergreen coniferous tree to 25 m or more, with spreading branches and a somewhat open crown. The needles are borne in fascicles of five, and are notably long, slender and pendulous, drooping gracefully and distinguishing it from the related P. wallichiana. The species is monoecious, with small pollen cones clustered at the base of new shoots and erect young seed cones that mature in the second year. The mature cone is large, cylindrical and resinous, with thin woody scales; the seeds are winged for wind dispersal, borne beneath the cone scales.

Pinus bhutanica was described as recently as 1980 and belongs to subgenus Strobus (the soft or white pines), being closely allied to the widespread Himalayan blue pine P. wallichiana, from which it differs chiefly in its longer, conspicuously drooping needles and more pronounced resin glands. Its narrow eastern Himalayan range makes it of biogeographic interest as a regional endemic of the wetter Bhutan-Arunachal sector; it is assessed by IUCN as Least Concern owing to stable populations within extensive forest.

Author: Grierson, D.G.Long & C.N.Page · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, IUCN Red List of Threatened Species, Farjon Handbook of the World's Conifers, Grierson Long & Page protologue of Pinus bhutanica

Pinaceae

Pinus roxburghii

by G & P Jürgens

Sarg.

Bhutan2012 531
Bhutan Wangdi, Phodrang 2400m, September
Bhutan2015 312
Bhutan, Trongsa 2100m, October

Description

Pinus roxburghii, the chir or longleaf Himalayan pine, is the dominant conifer of the dry outer ranges and inner valleys of the Himalaya, native across India, Nepal, Bhutan, Pakistan, Afghanistan and China, and widely planted elsewhere, as reflected by occurrence records from South Africa, the United States, New Zealand and Europe. It forms extensive open forests on warm, sun-exposed slopes, ridges and rain-shadowed valleys, characteristically between about 500 and 2300 m. The trees photographed near Wangdi Phodrang at 2400 m and Trongsa at 2100 m in Bhutan illustrate its presence in the dry inner Himalayan valleys, where it forms the lower montane pine belt below the broad-leaved and fir zones.

It is a large evergreen tree with a tall, often clear bole and a rounded to spreading crown, the thick bark deeply fissured into reddish-brown plates that confer fire resistance. The needles are borne in fascicles of three, long, slender and pendulous, light green and finely serrulate, with a persistent basal sheath. It is monoecious: the male strobili cluster at the base of new shoots, while the woody seed cones are large, ovoid-conical and hard, the cone scales bearing a stout, recurved umbo. The winged seeds are released at maturity and dispersed by wind.

Pinus roxburghii belongs to the hard pines (subgenus Pinus) and is the characteristic fire-adapted, drought-tolerant pioneer of the Himalayan subtropical pine forest, regenerating vigorously after burning and forming nearly pure stands. It is economically important as a source of resin (oleoresin tapped for turpentine and rosin), construction timber and fuelwood. Though not threatened given its vast range, its needle litter and flammability strongly shape fire regimes and understorey composition across the lower Himalaya.

Author: Sarg. · Sources: POWO (Kew), GBIF, Flora of China, Conifers of the Himalaya, Annotated Checklist of the Flowering Plants of Nepal, Farjon's A Handbook of the World's Conifers

Pinaceae

Pinus wallichiana

by G & P Jürgens

(Wall. ex. D.Don) A.B.Jacks.

Bhutan2014 544
Bhutan, Phobjika 3000m, May
Bhutan2014 961
Bhutan, Haa-valley, 2800m, May
Bh2008 295 P454
Bhutan, Ura 2900m, April

Description

Pinus wallichiana, the Bhutan or blue pine, is a major timber conifer of the Himalaya and Hindu Kush, ranging from Afghanistan and Pakistan through Kashmir, the Indian Himalaya, Nepal and Bhutan to south-eastern Tibet and China. It is among the best-recorded Himalayan trees, GBIF holding over 2400 occurrences, many from cultivation in Europe, North America and Australasia where it is a graceful ornamental. Natively it forms montane forests, often with Picea, Abies and Cedrus, on well-drained slopes between about 1800 and 4000 m. The Bhutanese stands at Phobjikha, the Haa valley and Ura between 2800 and 3000 m exemplify its dominance in the temperate conifer belt.

It is a large evergreen tree to 40 m or more, with a straight trunk, greyish fissured bark and whorled spreading branches forming a broad conical crown. The needle leaves are five per fascicle, slender, soft and drooping, 12 to 20 cm long, glaucous-bluish (whence blue pine) and finely serrulate. It is monoecious: small yellow pollen cones cluster at the base of new shoots, while the seed cones are long-pedunculate, cylindrical and resinous, 15 to 30 cm long and pendent, with broad woody scales spreading at maturity, each fertile scale bearing two winged, wind-dispersed seeds.

A member of Pinus subgenus Strobus (the soft or white pines, section Quinquefoliae), P. wallichiana is allied to P. griffithii and other five-needle pines of eastern Asia and North America, distinguished by its long pendulous cones and drooping foliage. It is important for construction timber, resin and fuel, and ecologically as a pioneer colonising landslides and abandoned terraces. Though widespread and not threatened, it is locally susceptible to blister rust and to over-exploitation near settlements.

Author: (Wall. ex. D.Don) A.B.Jacks. · Sources: POWO (Kew), GBIF, Flora of China Vol. 4, Flora of Bhutan Vol. 1, Flora of Pakistan, Farjon A Handbook of the World's Conifers