Author

GP Jürgens

Melastomataceae

Sonerila khasiana

by GP Jürgens

C.B.Clarke

Bhutan2015 138
Bhutan Galephug 600m, October
Bhutan2015 142
Bhutan Galephug 600m, October

Description

Sonerila khasiana is a small herb of the eastern Himalayan and northeast Indian region, recorded from India, Nepal, Bhutan, China and Myanmar, with comparatively few documented collections. It is a shade-loving plant of moist, humus-rich forest floors, shaded rock faces and damp banks in subtropical and lower montane forest, typically below about 1500 m. The illustrated plant from Galephug in southern Bhutan, at around 600 m and flowering in October, is characteristic of its lowland, post-monsoon flowering habit in warm, perpetually humid foothill forest where deep shade and constant moisture prevail.

The species is a delicate, often somewhat succulent annual or short-lived perennial with slender, ascending, frequently reddish stems. The leaves are opposite, ovate to elliptic, serrulate and traversed by the curved, parallel-converging nervation diagnostic of the Melastomataceae, the lamina often sparsely setose. The inflorescence is a short, terminal, scorpioid cyme of few flowers. The flowers are trimerous, with three pink to rose-purple petals and typically three stamens bearing the conspicuous, yellow, beaked anthers characteristic of the genus; the fruit is a small, three-angled, top-shaped capsule releasing numerous minute seeds.

The epithet refers to the Khasi Hills of Meghalaya, a centre of diversity for the genus. Sonerila is a large palaeotropical genus notable for its consistently trimerous flowers, unusual within a predominantly pentamerous family, and for its many narrow-range, forest-floor endemics. With relatively few records and a dependence on undisturbed shaded forest, such species are potentially sensitive to deforestation, although its full conservation status remains insufficiently assessed.

Author: C.B.Clarke · Sources: POWO (Kew), GBIF, Flora of China Vol. 13, Flora of Bhutan Vol. 2, Flora of Nepal, Revision of Sonerila (Melastomataceae)

Orobanchaceae

Sopubia trifida

by GP Jürgens

Buch.-Ham. ex D. Don

Bh09 353 P569
Bhutan Wangdi, 2400m June
Bh09 354 G570
Bhutan Wangdi, 2600m June

Description

Sopubia trifida Buch.-Ham. ex D.Don is a slender hemiparasitic herb of broad palaeotropical distribution, recorded across South and Southeast Asia and tropical Africa, including China, India, Nepal, Bhutan, Myanmar, Thailand, Indonesia, the Philippines, Sri Lanka, Madagascar, Papua New Guinea and several African nations; GBIF lists around 840 occurrences. It favours open grassy slopes, savanna, terraced field margins, scrub and disturbed sunny ground, mostly from the lowlands up to about 2700 m. The photographed plants were collected near Wangdi in Bhutan at 2400 and 2600 m in June, in the open warm-temperate grassland where this erect parasite grows attached to the roots of grasses.

The plant is an erect annual or perennial herb with stiff, wiry, often branched and minutely scabrous stems. The leaves are opposite below and alternate above, narrowly linear, sessile and frequently divided into a few filiform segments, the epithet trifida referring to this three-parted condition. The flowers are borne in lax terminal spike-like racemes; the corolla is rotate, typically pink to rose-purple, with a short tube and five subequal spreading lobes, while the calyx is campanulate and ribbed. The fruit is a small ovoid, loculicidal capsule containing numerous minute, angular seeds.

Now placed in the broadly recircumscribed Orobanchaceae following the transfer of hemiparasitic genera from the former Scrophulariaceae, Sopubia is a facultative root parasite drawing water and nutrients from neighbouring grasses through haustoria while retaining photosynthetic capacity. Its wide tropical range and tolerance of disturbed grassland account for its abundance. The species is common and not of conservation concern, and is sometimes regarded as a weedy associate of pastures and fallow land.

Author: Buch.-Ham. ex D. Don · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora of Ceylon, Fischer revision of Sopubia and allied Orobanchaceae

Rosaceae

Sorbus microphylla

by GP Jürgens

Wenz.

Bhutan2015 371
Bhutan Tumching-La 4000m, October
Bhutan2012 906
Bhutan Tumching-La 3900m, October
Bhutan2012 907
Bhutan Tumching-La 3900m, October

Description

Sorbus microphylla is a high-montane to subalpine deciduous shrub or small tree distributed along the Himalayan arc from Pakistan through Nepal, northern India, Sikkim and Bhutan into south-central China and Myanmar, with the GBIF dataset recording some 344 occurrences including ex-situ collections in Britain, Belgium and North America. It occupies open coniferous and Rhododendron forest, forest margins and alpine thickets, typically between 3000 and 4300 m. The photographed plants were gathered at Tumching-La in Bhutan at 3900-4000 m in October, the fruiting season, where the species forms part of the krummholz and dwarf-shrub community below the treeline.

It is a slender shrub, often 1-3 m tall, with reddish-brown to purplish glabrescent young branches bearing conspicuous lenticels. The leaves are imparipinnate with 10-15 or more pairs of small, crowded, oblong leaflets that are sharply serrate toward the apex, dark green above and paler beneath, turning rich crimson in autumn, the rachis often narrowly winged. The white to pinkish flowers are borne in small terminal corymbs, each with five petals, numerous stamens and two to three styles. The fruit is a small globose pome, white, pink-tinged or pale rose, 6-8 mm across, persisting after leaf-fall.

The species belongs to Sorbus subgenus Albocarmesinae, the white- and pink-fruited Himalayan-Sino mountain ashes, a complex group in which apomixis and hybridisation blur species limits. Its small leaflets and pale fruits distinguish it from related S. ursina and S. foliolosa. The pomes are an important autumn food for thrushes and other montane birds, which disperse the seed. Widespread and locally common across a broad range, it is not considered threatened, though valued horticulturally for its delicate foliage and persistent rosy fruit.

Author: Wenz. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, McAllister: The Genus Sorbus

Rosaceae

Sorbus thibetica

by GP Jürgens

(Cardot) Hand.-Mazz.

Bhutan2015 495
  Bhutan Pele-La 3000m, October
Bhutan2015 497
  Bhutan Pele-La 3000m, October

Description

Sorbus thibetica is a Sino-Himalayan whitebeam distributed along the eastern Himalaya and adjacent China, from Nepal through northern India, Sikkim and Bhutan into south-western China (Xizang, Yunnan) and northern Myanmar; its roughly 470 georeferenced occurrences include numerous cultivated records in Britain and northern Europe (GB, NO, DK), reflecting its long-standing horticultural use. It grows in temperate and subalpine forest, woodland margins, rocky slopes and open hillsides, generally between about 2500 and 3600 m. The tree photographed at Pele-La in Bhutan at 3000 m in October, in autumn fruit and leaf-colour, is typical of its cool, montane forest habitat.

It is a deciduous tree to 10-20 m, with a rounded crown and grey bark; the stout twigs and buds are densely white-tomentose when young. The leaves are simple (not pinnate), broadly elliptic to obovate, entire-leaved members of the Aria group, dark green and glabrescent above but persistently covered beneath with a thick, silvery-white felted tomentum, the margins finely and shallowly toothed. The white flowers are borne in flat-topped corymbs, each with five petals, numerous stamens and an inferior ovary. The fruit is a small subglobose pome, ripening orange-brown to russet and bearing scattered lenticels, typical of the simple-leaved whitebeams.

Sorbus thibetica belongs to the Aria group of simple-leaved whitebeams (sometimes segregated as the genus Aria), distinct from the pinnate-leaved rowans of Sorbus sensu stricto. The selection 'John Mitchell', with very large leaves, is widely grown ornamentally. Apomixis and hybridisation complicate species limits throughout the group. Widespread and frequent, it is not considered threatened.

Author: (Cardot) Hand.-Mazz. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora of Nepal, McAllister's The Genus Sorbus: Mountain Ash and other Rowans

Asteraceae

Soroseris depressa subst. depressa

by GP Jürgens

unknown

Bhutan2012 281
Bhutan Shele-La, 4100m September

Description

Soroseris depressa is a cushion-forming alpine composite of the high Himalaya and Tibetan margins, documented from Bhutan, India, China, Nepal and Japan, with about 62 GBIF occurrences. It is a specialist of the highest open ground, colonising scree, gravelly alpine turf, moraines and stony flats well above the treeline, commonly between about 4000 and 5000 m. The photographed material comes from the Shele-La in Bhutan at 4100 m in September, a wind-exposed pass where the species hugs the substrate among sparse alpine cushion vegetation late in the season.

The plant is a low, compact perennial herb with a stout, deep-seated taproot and a contracted, often subterranean caudex from which the leaves and capitula are densely crowded at ground level, forming a flattened ("depressa") rosette or cushion. The leaves are linear-oblanceolate to spathulate, entire to pinnatifid, and frequently woolly or glandular. The capitula are aggregated into a dense, head-like synflorescence sunk among the leaves; each is ligulate with yellow to whitish strap-shaped florets, enclosed by an involucre of few phyllaries. The fruit is a slender, ribbed cypsela crowned by a pappus of fine bristles.

Soroseris is a small genus of the tribe Cichorieae endemic to the Sino-Himalayan and Tibetan high mountains, and S. depressa (also treated under the name Tibetoseris depressa) exemplifies the extreme cushion habit evolved in response to cold, desiccation and short growing seasons. Its restriction to fragile high-alpine substrates makes it sensitive to climate warming and trampling, though its remote habitat affords some protection.

Author: unknown · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Systematics of Cichorieae (Asteraceae)

Asteraceae

Soroseris pumila

by GP Jürgens

Stebbins

Sikkim2003 292 P406 2
Sikkim Dzongri 4300m August

Description

Soroseris pumila is a high-alpine cushion composite restricted to the eastern Himalaya, recorded from Nepal, northern India (Sikkim) and Bhutan, with only about 97 GBIF records reflecting both its narrow range and the inaccessibility of its habitat. It is a plant of the upper alpine and subnival zones, growing on open screes, gravelly flats, moraine and stony turf well above the treeline, typically between about 4000 and 5000 m. The Sikkim population imaged at Dzongri at 4300 m in August captures the species in its characteristic late-summer flowering, when the brief post-snowmelt growing season allows these dwarf perennials to bloom and set seed.

The plant is a diminutive, often almost stemless perennial with a stout, deep taproot and a congested rosette or low tuft of leaves pressed close to the substrate, an adaptation to wind, cold and intense irradiation. The leaves are narrowly oblanceolate to spathulate, entire to pinnately lobed, and the foliage exudes milky latex when broken. The capitula are crowded into a dense terminal cluster nestled among the leaves; each head is ligulate with yellow ray florets, the corollas five-toothed. The fruit is a cypsela bearing a pappus of soft white bristles that facilitates wind dispersal across the open high-mountain terrain.

Soroseris is a small genus of cushion-forming lactucoid composites endemic to the high mountains of the Sino-Himalaya, and S. pumila is among the most reduced, dwarfed members, its compact habit typical of the subnival flora. Its restricted distribution and specialised habitat at the upper limit of plant life make it a notable element of eastern Himalayan alpine biogeography; while not formally assessed, such narrow-range high-elevation endemics are intrinsically vulnerable to climatic warming and habitat shift.

Author: Stebbins · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Stebbins' revision of Soroseris and Crepidinae (monograph)

Orchideaceae

Spathoglottis ixioides

by GP Jürgens

(D.Don) Lindl.

Bhutan2015 77
Bhutan Wangdi Galegphug 1500m, October
Bhutan2012 641
Bhutan Tserang 1600m, September
Bhutan2012 642
Bhutan Tserang 1600m, September

Description

Spathoglottis ixioides is a small terrestrial orchid of the Himalaya, recorded from Nepal, India, Bhutan and China, a relatively narrowly distributed species with 146 occurrences in GBIF. It grows on open grassy banks, mossy rock ledges, humus-rich slopes and forest margins, generally between 1500 and 3500 m. The Bhutanese localities given, Wangdi Galegphug at about 1500 m in October and Tserang at 1600 m in September, reflect the warm-temperate to subtropical montane grassland and bank habitats where it flowers in the post-monsoon autumn, often among grasses on damp, partly shaded ground.

The species is a dwarf, deciduous, terrestrial herb growing from a small subterranean pseudobulb or corm-like tuber. From this arise a few narrowly lanceolate, plicate (longitudinally pleated) leaves that taper to a slender base. The slender erect inflorescence carries one to a few comparatively large flowers; the floral segments are bright yellow, with spreading ovate-lanceolate sepals and petals and a distinctly three-lobed labellum bearing raised keels or calli on the disc and small lateral lobes flanking the column. The fruit is a small ellipsoid dehiscent capsule releasing numerous dust-like seeds.

Spathoglottis (subtribe Collabiinae, tribe Collabieae of the Epidendroideae) is chiefly a tropical Asian and Pacific genus, and S. ixioides is among its most cold-tolerant, high-altitude members, the yellow flowers and reduced deciduous habit distinguishing it within the genus. Like most terrestrial orchids it depends on mycorrhizal fungi for germination of its minute seeds and is pollinated by bees. Although locally frequent in suitable habitat, its restricted range, specialised ecology and the broad pressures of habitat disturbance and orchid collection warrant monitoring, and all orchids are listed under CITES Appendix II.

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

Asteraceae

Sphaeranthus indicus

by GP Jürgens

Gaertn.

Nepal 97 49 P74
Nepal Mewa-Khola 1100m April

Description

Sphaeranthus indicus Gaertn. is a widespread weedy annual of the Old World tropics and subtropics, with a very broad GBIF footprint (over 1200 occurrences) spanning India, Sri Lanka, Bangladesh, Nepal, Bhutan, Myanmar, Thailand, Laos, Vietnam, southern China and Indonesia, and extending to Australia, Madagascar, Kenya and Ethiopia. It is a plant of seasonally wet, open ground: rice-field margins, fallows, ditches, damp wastelands and the receding edges of pools and tanks, mostly at low elevations. The specimen photographed at Mewa-Khola in Nepal at 1100 m in April occurs in the warm subtropical foothill belt at the upper margin of its lowland range, where post-monsoon wet ground provides its preferred germination sites.

It is a strongly aromatic annual herb with a much-branched, often reddish, ascending to spreading stem bearing conspicuous toothed or undulate wings formed by the decurrent leaf bases. The leaves are obovate to oblanceolate, sessile, and serrate-dentate. The diagnostic feature is its compound capitulescence: numerous tiny, narrow secondary heads are aggregated into a dense, globose to ovoid, purple to violet compound head terminating each branch. Each small head contains a few peripheral female florets and central bisexual florets with tubular corollas. The fruit is a minute, oblong cypsela lacking a conspicuous pappus.

The genus Sphaeranthus is distinctive within tribe Inuleae for its glomerulate, second-order capitula, and S. indicus is its most familiar and economically significant species, valued throughout South Asia in Ayurvedic and folk medicine for its essential oils and bioactive sesquiterpenoids and flavonoids. Ecologically it behaves as a pioneer of disturbed, periodically inundated soils and is locally abundant; it is of least conservation concern and indeed often regarded as a ruderal weed across its pantropical range.

Author: Gaertn. · Sources: POWO (Kew), GBIF, Flora of China, Flowers of the Himalaya, Annotated Checklist of the Flowering Plants of Nepal, Anderberg monograph of tribe Inuleae

Rosaceae

Spiraea bella

by GP Jürgens

Sims

Sikkim2011 38
Sikkim Lachung 2850m, June
Sikkim2011 194
Sikkim Lachung 2850m, June
Sikkim2011 196
Sikkim Lachung 2850m, June

Description

Spiraea bella is a deciduous shrub distributed along the Himalaya and into adjacent China, with verified occurrences spanning China, India, Nepal, Bhutan, Pakistan and Myanmar; further GBIF records from Japan, Korea and numerous European and North American countries reflect its long cultivation as an ornamental. It is a plant of temperate forest margins, open slopes, ravines and shrubberies, typically between about 2000 and 3500 m. The photographed material from Lachung in northern Sikkim at around 2850 m in June, in full bloom, exemplifies its montane habitat in moist, cool valleys.

The species forms an erect to spreading shrub usually 1-2 m tall with slender, angled, reddish-brown branchlets. The alternate, shortly petiolate leaves are ovate to ovate-lanceolate, sharply and often doubly serrate, green above and paler, sometimes thinly pubescent on the veins beneath. Flowers are crowded into terminal corymbs borne on short lateral shoots; each small flower has five rounded pink to rose petals and numerous stamens that exceed the petals, giving the inflorescence a feathery aspect. The fruit is an aggregate of small glabrous to sparsely hairy follicles that split along the inner suture to release minute seeds.

Spiraea bella belongs to a complex of pink-flowered Himalayan spiraeas allied to S. canescens and S. japonica, within which leaf shape and indumentum provide the principal diagnostic characters. Long valued in gardens for its early-summer flowering, it functions ecologically as a nectar source for insects and a component of regenerating forest-edge scrub. It is widespread and locally common, and faces no recognised conservation threat across its broad native range.

Author: Sims · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flowers of the Himalaya

Orchideaceae

Spiranthes sinensis

by GP Jürgens

(Pers.) Ames

Bhutan2014 92
Bhutan Trashigang 1450m, May
Bh2008 471 G732
Bhutan Tsang-Chu, 1800m April
Nepal1992 92 P126 ergebnis
Nepal Amjilassa 2300m March 

Description

Spiranthes sinensis, the Chinese ladies'-tresses, is one of the most widespread terrestrial orchids of the Old World, documented in GBIF by some 7880 occurrences spanning eastern Asia from China, Japan, Korea and Russia through India, Nepal, Bhutan and Southeast Asia to Australia, New Caledonia and Sri Lanka. It occupies open, moist grassland, marshy meadows, streambanks, paddy margins and grassy slopes from near sea level to about 3000 m. The photographed Himalayan plants from Trashigang in Bhutan at 1450 m in May, the Tsang-Chu at 1800 m in April and Amjilassa in eastern Nepal at 2300 m in March illustrate its tolerance of a wide elevational and seasonal range in damp, sunny situations.

It is a slender terrestrial orchid with fleshy, fasciculate, tuberous roots and a tuft of linear to oblanceolate basal leaves. The erect, finely pubescent inflorescence bears numerous small flowers arranged in a characteristic single spiral around the axis. The flowers are typically pink to rose-purple with a white, recurved, crisped-margined labellum bearing a yellowish, papillose central callus; the dorsal sepal and petals converge to form a hood over the short column. The fruit is a small, erect, ellipsoid capsule releasing dust-like seeds.

A member of subtribe Spiranthinae of the Orchidaceae (here under the input spelling Orchideaceae), S. sinensis forms a taxonomically complex, polyploid-rich aggregate from which several segregates such as S. australis and S. hongkongensis have been recognised. Like most orchids it depends on mycorrhizal fungi for germination and is pollinated chiefly by bees. Despite local declines from wetland drainage, its enormous range and weedy persistence in disturbed grassland make it of Least Concern, though it is protected under CITES Appendix II as for all orchids.

Author: (Pers.) Ames · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Pridgeon et al. Genera Orchidacearum