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.

Iridaceae

Iris clarkei

by GP Jürgens

Baker ex Hook.f.

BhutanPG2011 773 01 01
Bhutan Chele-La, 3900m June
Bh09 35 P65
Bhutan Dochu-La, 3000m June
Bh09 206 P346
Bhutan Dochu-La, 3000m June

Description

Iris clarkei is an eastern Himalayan beardless iris distributed through Bhutan, Sikkim and northeastern India, Nepal, southern Tibet (China) and northern Myanmar, with GBIF holding about 174 occurrences. It is a subalpine to alpine moisture-lover, recorded here from two Bhutanese passes, Chele-La at 3900 m and Dochu-La at 3000 m, both flowering in June. The species favours wet alpine meadows, marshy hollows, stream sides and seasonally flushed turf on slopes, typically between roughly 3000 and 4300 m, where it forms colonies in the open, moist grassland of the upper temperate and subalpine zones.

It is a tufted rhizomatous perennial of the Sibiricae group, with slender creeping rhizomes producing erect, solid (not hollow) flowering stems that are characteristically branched and bear a distinctive solid pith. The leaves are linear-ensiform, grass-like, ribbed and grouped in basal fans. Each stem carries one to several flowers; the perianth is blue-violet to reddish-purple, the spreading or deflexed falls bearing a paler, conspicuously veined and blotched signal patch, and the standards are smaller and more erect, the flowers beardless and crestless. The fruit is a three-angled loculicidal capsule containing flattened seeds.

Described by Baker (ex Hook.f.) and named for C. B. Clarke, the species belongs to series Sibiricae, the Asian relatives of Iris sibirica, and is of horticultural interest for its solid stems and richly marked falls. Though restricted to specialised wetland habitats, it remains locally common within its range; pressures such as grazing, trampling and drainage of montane mires are the principal local threats to its boggy habitat.

Author: Baker ex Hook.f. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Mathew The Iris, British Iris Society A Guide to Species Irises

Iridaceae

Iris decora

by G & P Jürgens

Wall.

Nepal 99 13 ergebnis
West-Nepal, Jumla 2500m june
Nepal 99 14 ergebnis
West-Nepal, Jumla 2500m june

Description

Iris decora Wall. is a tuberous-rooted iris of the Himalaya and the mountains of southwestern China. GBIF data confirm its presence in Nepal, India, Bhutan, Pakistan, China and Myanmar, a range extending the length of the Himalayan arc into Yunnan. It grows on open grassy hillsides, stony slopes and among scrub in the temperate zone, characteristically between about 1,800 and 3,300 m. The plant recorded near Jumla in west Nepal at 2,500 m, flowering in June, typifies its early-summer flowering on sunny montane meadows.

The species arises from a cluster of slender, fleshy, fascicled roots rather than a true rhizome, and produces narrow, grass-like, ribbed leaves that develop fully after flowering. The flowering stem is short, bearing one to several flowers in succession, each subtended by membranous spathe valves. The flowers are lilac to pale violet-blue, the falls bearing a conspicuous yellow or white crest along the central ridge and the standards smaller and erect. The capsule is oblong-cylindric with a beaked apex, splitting to release numerous seeds.

Iris decora belongs to the subgenus Nepalensis (section Pseudoregelia in older treatments), a small group of Sino-Himalayan irises characterised by fascicled fleshy roots and crested falls. It is grown by alpine-plant enthusiasts and is the type of its species group. Although locally common in suitable grassland, it is vulnerable to overgrazing and habitat conversion in the more accessible parts of its range.

Author: Wall. · Sources: POWO (Kew), GBIF, Flora of China Vol. 24, Flora of Bhutan Vol. 3, Mathew: The Iris (1989)

Iridaceae

Iris dolichosiphon

by GP Jürgens

Noltie

Bh09 30 G56
Bhutan Shele-La 4000m, June
Bh09 31 P57
Bhutan Shele-La 4000m, June

Description

Iris dolichosiphon is a high-alpine dwarf iris restricted to the eastern Himalaya and adjacent China, a narrow-range endemic recorded by GBIF from only China, Bhutan and India, with a small total of around 77 occurrences reflecting both its limited distribution and the remoteness of its habitat. It grows in open alpine turf, meadows, grassy slopes and rocky pastures above the treeline, generally between about 3500 and 4500 m, where snow-melt and short cool summers govern its brief flowering season. The photographed plant from the Shele La in Bhutan, at roughly 4000 m and flowering in June, is exactly typical of its occurrence on exposed high passes, where it forms low cushions among short alpine vegetation soon after the snow recedes.

It is a small, tufted perennial of the dwarf-crested and beardless Himalayan iris assemblage, arising from a slender, fibrous-coated rhizome and producing narrow, linear, grass-like leaves. The flowers are nearly sessile at ground level but are raised, in effect, by an extremely long, slender perianth tube, the character that gives the species its epithet (dolichos, long; siphon, tube), so that the floral parts are presented well above the very short stem. The flowers are violet to lilac-blue, the three outer tepals (falls) spreading and signalled with a paler, veined and crested or ridged blaze, the three inner tepals (standards) smaller and erect; the three petaloid style branches arch over the stamens.

Described by H. J. Noltie, who clarified much of the Sino-Himalayan iris flora, I. dolichosiphon belongs to the alpine, beardless dwarf irises and is allied to species such as I. kemaonensis and the I. goniocarpa group, from which the conspicuously elongate perianth tube distinguishes it. Its pollination by long-tongued bumblebees is favoured by the deep tube, and seed is set in a capsule that ripens as the brief alpine season closes. As a narrowly distributed high-altitude endemic with few records, it warrants monitoring; while not formally assessed as threatened, its restricted range and sensitivity to climate-driven shifts in the alpine zone make it of biogeographic and conservation interest.

Author: Noltie · Sources: POWO (Kew), GBIF, Flora of China Vol. 24, Flora of Bhutan Vol. 3, Flora of Nepal, Flora of Pakistan, Noltie's account of the Sino-Himalayan irises

Iridaceae

Iris kemaonensis

by GP Jürgens

Wall. ex D.Don

Nepal 99 299 ergebnis
West-Nepal Kalmura 4200m, June
Nepal 99 298 ergebnis
West-Nepal Kalmura 4200m, June
Garh 07 172 ergebnis
India Garhwal Kinkhola 3545m, June

Description

Iris kemaonensis is a dwarf alpine iris of the Himalaya and adjacent ranges, distributed across Pakistan, Nepal, NW India, Bhutan and SW China, with 346 GBIF occurrences. It grows on open alpine meadows, grassy slopes, stony pastures and recently snow-freed ground in the upper subalpine to alpine zone. The cited collections from Kalmura in West Nepal at about 4,200 m and Kinkhola in Garhwal at 3,545 m, both in June, are characteristic of its early-summer flowering as snow melts on high turf, where it forms low scattered clumps.

It is a rhizomatous perennial with a short, stout, branching rhizome bearing fibrous remains of old leaves. The leaves are linear-ensiform, appearing with or shortly after the flowers and elongating considerably as the fruit ripens. The flowers are usually solitary and almost sessile at ground level, lilac to pale purple, mottled and spotted with deeper purple; the falls are obovate with a yellow or white beard along the median crest, the standards smaller and erect. The perianth tube is long and slender, raising the flower above the spathes. The fruit is a trigonous capsule, often borne on an elongating stalk emerging after anthesis.

The species belongs to Iris subgen. Pseudoregelia, the bearded, mottled-flowered, rhizomatous group centred on the Himalaya and Central Asia. GBIF records it as accepted. It is a charismatic, ground-hugging alpine bearing close ecological resemblance to other cushion-meadow geophytes, and remains widespread and unthreatened, though locally subject to grazing pressure.

Author: Wall. ex D.Don · Sources: POWO (Kew), Flora of China Vol. 24, Flora of Bhutan Vol. 3, GBIF, Mathew: The Iris (1989)

Iridaceae

Iris tectorum

by G & P Jürgens

Maxim.

Bhutan2014 42
Bhutan Trashigang 1200m, May
Bhutan2014 974
Bhutan Chele-La 3400m, May
Bhutan2014 975
Bhutan Chele-La 3400m, May

Description

Iris tectorum, the roof iris or wall iris, is native to China and long cultivated across East Asia, with naturalised and planted populations widely recorded; GBIF documents 1128 occurrences in China, Japan, Korea, the United States, India, Bhutan, Myanmar, Taiwan, Kazakhstan and parts of Europe. It grows on dry banks, grassy slopes, rocky ground and, famously, on thatched roofs and old walls where it was traditionally established. In Bhutan the illustrated plants span a wide range, from Trashigang at about 1200 m to Chele-La at 3400 m, both flowering in May, showing its tolerance of both warm valley and high-pass conditions.

The plant is a rhizomatous perennial with a stout, shortly creeping rhizome bearing tufts of broadly ensiform, soft, ribbed leaves arranged in flat fans. The flowering stem is branched and bears several large flowers; each has the iris structure of three spreading, reflexed outer perianth segments (falls) and three smaller erect inner segments (standards). The falls are pale lilac-blue, conspicuously veined and mottled with darker blue, and bear a fringed or crested white-and-violet ridge in place of a beard, identifying it as a crested (Evansia) iris. The three petaloid style branches arch over the stamens; the inferior ovary matures into an oblong, ridged loculicidal capsule releasing rounded seeds.

Assigned to subgenus Limniris and the crested-iris alliance, I. tectorum is a long-standing ornamental and the source material for traditional medicinal use of its rhizome. POWO and GBIF accept the name. Its frequent cultivation accounts for the scattered extralimital records far beyond its East Asian native range.

Author: Maxim. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, The Iris (Iridaceae monograph), Annotated Checklist of the Flowering Plants of Nepal

Lamiaceae

Isodon hispidus

by G & P Jürgens

(Benth.) Murata

Bhutan2015 29
Bhutan Dochu-La 2800m, October

Description

Isodon hispidus (Benth.) Murata is a perennial herb of the mint family distributed across the eastern Himalaya and the mountains of southern China and mainland Southeast Asia. GBIF records confirm its presence in Bhutan, India, China, Myanmar, Laos, Vietnam, Thailand and Korea, with an outlying record from Tanzania likely representing a cultivated or misidentified collection. It favours moist forest margins, shrubby clearings and open slopes in the temperate and subalpine zones, typically between 1,500 and 3,000 m. The photographed plant at the Dochu-La in Bhutan, at 2,800 m and flowering in October, exemplifies its preference for cool, humid montane habitats where autumn blooms persist after the monsoon.

The species forms an erect, branched herb 0.5–1.5 m tall arising from a woody rootstock, with quadrangular stems that are densely hispid with spreading hairs. The opposite leaves are ovate to broadly ovate, acuminate, with a coarsely serrate margin and a rugose, pubescent surface, narrowing to a winged petiole. The inflorescence is a lax terminal panicle composed of numerous cymes; the small flowers have a campanulate, two-lipped calyx and a pale violet to purplish corolla with the characteristic declinate lower lip of the genus, enclosing four exserted stamens. The fruit comprises four smooth, ovoid nutlets.

Isodon hispidus belongs to a large and taxonomically intricate genus (formerly placed in Rabdosia and Plectranthus) noted for diterpenoid chemistry of pharmacological interest. Several congeners are used in traditional Asian medicine, and the genus is a focus of phytochemical research into ent-kaurene diterpenoids. The species is widespread and not considered threatened across its broad range.

Author: (Benth.) Murata · Sources: POWO (Kew), GBIF, Flora of China Vol. 17, Flora of Bhutan Vol. 2, Murata: Revision of Asian Isodon (Lamiaceae)

Lamiaceae

Isodon lophanthoides

by G & P Jürgens

(Buch.-Ham. ex D.Don) H.Hara

Bhutan2015 586
Bhutan Mo-Chu 1800m, October
Bhutan2015 587
Bhutan Mo-Chu 1800m, October

Description

Isodon lophanthoides is a widespread herb of the Sino-Himalayan region, recorded from China, the Indian Himalaya, Nepal, Bhutan, Pakistan, Myanmar, Thailand, Laos, Vietnam, Bangladesh, Malaysia and Hong Kong, and represented by nearly two thousand georeferenced collections. It occupies a broad subtropical to warm-temperate belt, growing on moist shaded banks, forest margins, streamsides, grassy slopes and disturbed ground. In Bhutan it descends to warm river valleys, as along the Mo-Chu at about 1800 m where it was photographed flowering in October, the late-season anthesis typical of the genus.

The plant is an erect to ascending annual or short-lived perennial herb with quadrangular, often purple-tinged and pubescent or glandular stems. The leaves are opposite, ovate to broadly ovate, crenate-serrate, acuminate, and narrowed at the base into a winged petiole, often gland-dotted beneath. The inflorescence is a lax, much-branched terminal panicle of small cymes. The flowers have a bilabiate, glandular calyx that enlarges in fruit, and a small two-lipped corolla that is white to pale pink or purplish, dotted with darker spots, with a flat lower lip and four declinate didynamous stamens. The fruit consists of four smooth ovoid nutlets (mericarps).

Isodon (formerly included in a broad Rabdosia and Plectranthus) belongs to subfamily Nepetoideae of Lamiaceae; this species was described as Plectranthus lophanthoides by Buchanan-Hamilton and transferred by Hara. Several intraspecific varieties have been recognised across its range. Rich in bioactive ent-kaurane diterpenoids, it is used in Chinese herbal medicine, and its broad ecological tolerance and frequency mean it is not of conservation concern.

Author: (Buch.-Ham. ex D.Don) H.Hara · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora of Pakistan, taxonomic revisions of Isodon (Lamiaceae) by H. W. Li

Lamiaceae

Isodon scrophularioides

by G & P Jürgens

(Wall.) Murata

Bhutan2012 352
Bhutan Wangdi 2200m, October

Description

An erect perennial mint of the Himalaya and adjacent mountains, recorded from Nepal, China, India, Bhutan and Myanmar, with about 180 GBIF occurrences. It grows on open slopes, scrub margins, forest edges, roadbanks and disturbed clearings in the warm-temperate and subtropical zones, generally between about 1500 and 2800 m, flowering into the autumn. The illustrated plant was photographed in October at Wangdi in Bhutan at around 2200 m, a sunny mid-elevation montane site typical of its late-season flowering.

The species is a tall, branching herb or subshrub with the characteristic quadrangular stems of the mint family, often finely pubescent. The leaves are opposite and decussate, ovate to ovate-lanceolate, acuminate, with serrate margins and a glandular-punctate, aromatic surface, borne on distinct petioles. The inflorescence is a lax, much-branched terminal panicle of small cymes. Each flower has a campanulate, two-lipped calyx and a small bilabiate corolla, pale lilac to whitish or bluish, with a short tube, a four-lobed upper portion and a larger boat-shaped lower lip enclosing the four declinate stamens. The fruit comprises four small, smooth, ovoid nutlets seated in the persistent calyx.

Accepted by POWO and GBIF, I. scrophularioides belongs to the genus Isodon (formerly within Rabdosia and Plectranthus), a group of mints rich in bioactive diterpenoids and of interest in traditional medicine and phytochemistry. The deflexed lower lip forms a landing platform for bee pollinators, and the dry nutlets are dispersed by gravity and disturbance. Adaptable and frequent in secondary habitats across its range, it is of no conservation concern and exemplifies the largely Asian, montane radiation of the genus.

Author: (Wall.) Murata · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Li revision of Isodon

Lamiaceae

Isodon ternifolius

by G & P Jürgens

(D.Don) Kudô

Bhutan2015 461
Bhutan Trongtsa 2100m, October

Description

Isodon ternifolius is a shrubby mint distributed across the eastern Himalaya and Southeast Asia, recorded by GBIF (477 occurrences) from China, India, Thailand, Nepal, Myanmar, Vietnam, Bhutan, Bangladesh and Laos. It occupies forest margins, thickets, open hillsides, roadsides and disturbed slopes, mostly at lower to mid montane elevations between roughly 500 and 2500 m. The plant photographed at Trongsa in central Bhutan at 2100 m in October illustrates its autumn flowering, when the airy inflorescences come into bloom along forested valley margins toward the upper end of its altitudinal range.

The species is an erect perennial herb or soft shrub with quadrangular, often densely pubescent stems. As suggested by the epithet, the leaves are frequently borne in whorls of three (ternate), in addition to the opposite arrangement typical of the family; they are ovate to lanceolate, crenate-serrate and shortly petiolate, with a velvety to tomentose indumentum. The flowers are small and arranged in many-flowered thyrses formed of axillary cymes. The corolla is bilabiate with a short tube, the upper lip four-lobed and reflexed and the lower lip boat-shaped and declinate to enclose the four stamens and the bifid style. The fruit comprises four smooth, ovoid nutlets enclosed within the persistent campanulate calyx.

Isodon, long included within Plectranthus or Rabdosia, is now recognised as a distinct genus of Old World mints noted for its rich array of bioactive ent-kaurane diterpenoids, several species being used in traditional Chinese medicine. The nectariferous bilabiate flowers are pollinated by bees and other insects, and the nutlets are dispersed passively from the persistent calyces. The species is common, weedy in disturbed habitats and not regarded as threatened.

Author: (D.Don) Kudô · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora of Thailand, Revision of the Genus Isodon (Li)

Bignoniaceae

Jacaranda mimosifolia

by G & P Jürgens

D.Don

Bhutan2014 737
Bhutan Punaka 1200m, May

Description

Jacaranda mimosifolia is a deciduous tree native to subtropical South America, in particular northwestern Argentina and adjacent Bolivia, but it is now one of the most widely planted ornamental trees in warm-temperate and tropical regions worldwide; its more than twenty thousand occurrence records span Australia, South Africa, Spain, Kenya, Mexico, the United States and far beyond. It thrives in well-drained soils in warm valleys, parks and roadsides and is frost-sensitive. The tree photographed at Punakha in Bhutan at 1200 m in May is a cultivated street or garden specimen, flowering in its characteristic spring blaze in the warm lower Himalayan valley, well outside its native New World range.

It is a medium to large tree with a spreading, rounded crown and smooth grey bark. The leaves are large, opposite and bipinnate with many small, oblong, mucronate leaflets, recalling those of mimosoid legumes and giving the species its epithet. The flowers are produced in showy terminal panicles, typically before or with the new foliage; each has a small campanulate calyx and a tubular, two-lipped blue to violet corolla that swells above a narrow base. Four didynamous stamens and a staminode are enclosed within. The fruit is a flattened, woody, rounded to oblong capsule that splits along two valves to release numerous thin, broadly winged, wind-dispersed seeds.

Jacaranda is a Neotropical genus of the Bignoniaceae, and J. mimosifolia is its most familiar member, prized for its lavender-blue spring flowering. In its native range it is assessed as Vulnerable owing to limited and fragmented wild populations, even as it flourishes in cultivation globally; in several regions it has become naturalised or weedy. Its nectar-rich flowers attract bees and other insects, and its showy display has made it an emblematic urban tree across the subtropics.

Author: D.Don · Sources: POWO (Kew), GBIF, Flora Argentina, IUCN Red List assessment, Gentry's treatment of Bignoniaceae