Author

GP Jürgens

Fabaceae

Sunhangia elegans

by GP Jürgens

(DC.) H.Ohashi & K.Ohashi.

Bhutan2014 125
Bhutan Trashigang 1570m, May
Bhutan2014 126
Bhutan Trashigang 1570m, May

Description

Sunhangia elegans—long familiar as Desmodium elegans—is a shrubby legume widely distributed through the Himalaya and adjoining mountains of China, Nepal, India, Pakistan and Bhutan, with around 1611 occurrence records; the scatter of points in distant countries largely reflects cultivation and naturalisation of this popular ornamental. It grows on open hillsides, forest margins, scrub, roadsides and disturbed slopes, mostly in the warm-temperate to subtropical montane belt. The illustrated plant from Trashigang in eastern Bhutan at 1570 m, flowering in May, sits within this characteristic mid-elevation habitat.

It is a deciduous shrub with arching, much-branched stems bearing trifoliolate leaves; the leaflets are rhombic-ovate to broadly elliptic, the terminal one largest, green above and paler and finely pubescent beneath. The inflorescences are terminal and axillary panicles of many papilionaceous flowers ranging from pale lilac and pink to purple, with the typical standard, wing and keel petals and diadelphous stamens. The fruit is a flattened, jointed loment constricted between the seeds and breaking into one-seeded articles whose hooked hairs cling to fur and clothing, effecting epizoochorous dispersal.

The genus Desmodium has recently been dismembered on molecular evidence, with several Asiatic species transferred by H. Ohashi and K. Ohashi to segregate genera, here placed in Sunhangia, with the accepted combination Sunhangia elegans. Like other members of the tribe Desmodieae it forms root nodules with nitrogen-fixing rhizobia, enriching poor montane soils, and is valued both as fodder and as a hardy garden shrub. It is widespread and faces no recognised conservation concern.

Author: (DC.) H.Ohashi & K.Ohashi. · Sources: POWO (Kew), GBIF, Flora of China (Fabaceae), Annotated Checklist of the Flowering Plants of Nepal, Grierson & Long Flora of Bhutan, Ohashi & Ohashi's revision of the Desmodium group (Leguminosae)

Gentianaceae

Swertia bimaculata

by GP Jürgens

(Siebold & Zucc.) Hook. f. & Thomson ex C.B. Clarke

Bhutan2012 354
Bhutan Doch-La, 3000m September
Bhutan2012 355
Bhutan Doch-La, 3000m September
Bh2008 65 P106
Bhutan Punaka-Chu, 1600m April

Description

Swertia bimaculata is a widely distributed Asian gentian recorded by GBIF in nearly 3,942 occurrences spanning China, Japan, Korea, India, Bhutan, Nepal, Myanmar, Indonesia, Malaysia and Vietnam, making it one of the most far-ranging members of its genus. It occupies forest margins, grassy slopes, meadows and streamsides over a broad altitudinal span from lowland valleys to the subalpine zone. The Bhutanese collections illustrated, one from the Dochu La at 3000 m flowering in September and another from the Punakha Chu at 1600 m in April, demonstrate both its wide elevational tolerance and a flowering season extended by the diversity of habitats it occupies.

The species is a tall, erect annual or biennial herb with an angular, often branched stem arising from a slender taproot. The leaves are opposite, sessile to short-petiolate and broadly elliptic to lanceolate, with prominent arcuate veins. Flowers are numerous in a large, lax terminal panicle; the corolla is rotate and deeply four- to five-lobed, the lobes pale greenish-white to yellowish and finely dotted or streaked with purple. Each lobe bears two conspicuous dark glandular nectaries—the paired "two spots" of the epithet bimaculata—fringed with long fimbriae. The superior ovary develops into a narrowly ovoid septicidal capsule releasing many small seeds.

Swertia is a taxonomically complex, pharmacologically notable genus whose bitter secoiridoid-rich species are widely used in traditional Asian medicine, and S. bimaculata is among those harvested for such purposes. The fringed nectary glands and spotted corolla attract bees and flies that effect cross-pollination. Despite its medicinal exploitation the species remains common and ecologically plastic across its enormous range and is not regarded as threatened.

Author: (Siebold & Zucc.) Hook. f. & Thomson ex C.B. Clarke · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora of Japan, Revision of the Genus Swertia (Hara)

Gentianaceae

Swertia cordata

by GP Jürgens

(G. Don) Wall. ex. C.B. Clarke

Bhutan2015 464
Bhutan Trongsa 2100m, October
Garw 2005 276 ergebnis
India Garhwal Kunol 2600m, September

Description

Swertia cordata is a Himalayan gentian relative ranging along the entire arc from Afghanistan and Pakistan through India, Nepal, Bhutan and into south-western China and Myanmar, documented by some 332 GBIF records. It favours moist, shaded banks, grassy forest clearings, stream margins and humid open slopes within the temperate zone, broadly between 1800 and 3000 m. The material illustrated from Trongsa in central Bhutan at 2100 m in October and from Kunol in the Garhwal Himalaya at 2600 m in September reflects its late-season flowering, when the post-monsoon humidity sustains the soft foliage of this short-lived herb.

It is an erect annual or biennial with a slender, quadrangular and often branched stem. The basal and lower cauline leaves are conspicuously cordate at the base and shortly petiolate, while the upper leaves become sessile and amplexicaul; all are thin, ovate and prominently veined. The flowers are borne in lax terminal and axillary cymose panicles, the corolla typically four-merged, rotate and pale blue to lilac with darker veining, each lobe bearing the nectary pits or foveae diagnostic of Swertia, fringed by scale-like appendages. The fruit is a septicidal capsule containing numerous small seeds.

Swertia is a large, taxonomically demanding genus widely exploited in Himalayan ethnomedicine for its bitter secoiridoid glycosides, and S. cordata shares this chemistry. The basal foveae govern a specialised pollination relationship in which nectar is hidden beneath protective fringes. The species is not regarded as threatened given its wide distribution, but collection for medicinal use and habitat loss along forest margins warrant monitoring of accessible populations.

Author: (G. Don) Wall. ex. C.B. Clarke · Sources: POWO (Kew), GBIF, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Flora of China (Gentianaceae), Revision of the genus Swertia

Gentianaceae

Swertia cuneata

by GP Jürgens

D. Don

Bhutan2012 299
Bhutan Shale-La, 4300m September

Description

Swertia cuneata is a Himalayan gentian relative distributed from Pakistan through India, Nepal, China and Bhutan, with around 157 GBIF records. It is a plant of the alpine and upper subalpine zone, growing in open meadows, turfy slopes, rocky pastures and streamsides, broadly between about 3500 and 4500 m. The gathering from the Shale-La in Bhutan at 4300 m in September documents its late-summer flowering, when these high passes carry a colourful display of gentians, swertias and other alpine herbs at the close of the monsoon.

It is an erect annual or short-lived perennial herb with a simple or branched, often four-angled stem. The leaves are opposite, sessile, oblong to lanceolate and cuneate (wedge-shaped) at the base, the feature recalled by the epithet "cuneata". The flowers are borne in terminal and axillary cymes forming a loose panicle; each is rotate and four- or five-merous, with spreading lobes that are pale blue to purplish or yellowish and conspicuously veined or spotted, and bearing the nectary glands (nectaries fringed with fimbriae) on the corolla lobes that are diagnostic of Swertia. The fruit is a septicidal capsule containing numerous small seeds.

Swertia belongs to tribe Gentianeae and is well diversified in the Sino-Himalayan alpine flora, distinguished from Gentiana by its deeply divided, wheel-shaped corollas with open nectar glands rather than a tubular flower. Several species are important in Himalayan traditional medicine (the "chiretta" group), and although S. cuneata itself is widespread and not of conservation concern, harvesting pressure affects related taxa. Pollination is by generalist insects attracted to the exposed nectaries.

Author: D. Don · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Swertia revision (Clarke / Ho & Liu)

Gentianaceae

Swertia hookeri

by GP Jürgens

C.B. Clarke

Sikkim2003 447 P620
Sikkim Chopta Valley 3800m August
Sikkim2003 448 K620.2
Sikkim Chopta Valley 3800m August

Description

Swertia hookeri is an eastern Himalayan gentian of comparatively restricted range, recorded from India (chiefly Sikkim and Darjeeling), Nepal, Bhutan and the bordering provinces of southern China, GBIF holding around 63 occurrences consistent with a regional endemic. It inhabits moist alpine and upper subalpine zones, growing on open grassy slopes, among shrubberies, on rock ledges and along stream margins where snowmelt maintains high soil moisture. The plant photographed in August in the Chopta Valley of Sikkim at about 3800 m is typical of its elevation band, flowering at the height of the monsoon when the alpine turf is lush and humid.

It is a robust perennial or biennial herb with a stout, erect, often purple-tinged stem arising from a thick rootstock. The leaves are largely basal, broadly elliptic to ovate, conspicuously several-nerved and narrowed to a sheathing base, the cauline leaves becoming smaller and sessile upward. The inflorescence is a leafy branched panicle of large, broadly campanulate flowers; the corolla is usually 4- or 5-merous, pale greenish-yellow to whitish and densely veined with purplish-blue reticulation, each lobe bearing a pair of fimbriate nectary pits at the base. Stamens alternate with the lobes, and the superior ovary develops into a septicidal capsule with numerous small seeds.

Described by C. B. Clarke, Swertia hookeri belongs to a large, taxonomically intricate genus centred on the Sino-Himalayan region, forming part of a species swarm noted for diagnostic nectary morphology. Like many congeners it is rich in bitter secoiridoid and xanthone compounds and is gathered locally for medicinal and febrifugal use. Its dependence on intact high-altitude grassland renders it potentially sensitive to grazing pressure and climate-driven treeline shifts, though it has not been formally evaluated.

Author: C.B. Clarke · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Hara Flora of Eastern Himalaya, Clarke revision of Swertia

Gentianaceae

Swertia macrosperma

by GP Jürgens

(C.B. Clarke) C.B. Clarke

Bhutan2015 31
Bhutan Thimphu 2300m, October
Bhutan2012 321
Bhutan Dochu-La, 3100m September
Bhutan2012 322
Bhutan Dochu-La, 3100m September

Description

Swertia macrosperma is a widespread gentian-family herb of Asia, exceptionally well represented in GBIF with about 1613 occurrences spanning Taiwan, China, India, Nepal, Bhutan, Myanmar, Bangladesh, Japan and beyond. It is a plant of open, moist montane settings, growing on grassy slopes, forest margins, clearings, banks and damp meadows in the temperate to lower subalpine belt. The material photographed in Bhutan, at Thimphu around 2300 m in October and at the Dochu-La pass near 3100 m in September, illustrates its autumn flowering season, when these post-monsoon slopes carry the late display typical of many Himalayan swertias.

It is an erect annual to biennial herb with slender, often quadrangular and branched stems arising from a basal rosette of leaves. The cauline leaves are opposite, sessile to shortly petiolate and ovate to lanceolate. The flowers are borne in lax terminal and axillary cymes forming a diffuse panicle; each is usually four- or five-merous with a rotate, deeply parted corolla that is whitish, pale greenish or tinged with purple and frequently spotted, and each corolla lobe bears one or two fringed nectary glands (foveolae) diagnostic of the genus. The fruit is a septicidal capsule that, as the epithet indicates, releases comparatively large seeds.

Swertia is a large genus of tribe Swertieae, distinguished from Gentiana by its rotate, deeply divided corolla and conspicuous nectary pits. Several species, including this one, are gathered for traditional medicine on account of their bitter secoiridoid compounds. As an abundant and ecologically tolerant species across a vast range, S. macrosperma is of no conservation concern, though localised harvesting pressure on bitter Swertia species is documented elsewhere in the genus.

Author: (C.B. Clarke) C.B. Clarke · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora of Nepal, Ho & Pringle Gentianaceae revision

Gentianaceae

Swertia multicaulis

by GP Jürgens

D. Don

Sikkim2003 301 G422
Sikkim Saniti-Lake 4250m August

Description

Swertia multicaulis is a high-alpine Himalayan gentian distributed through Nepal, China, India, Bhutan and recorded marginally from Kazakhstan, with GBIF holding around 144 occurrences along the main Himalayan chain. It is a plant of the upper alpine zone, growing on damp, peaty or gravelly meadows, moist rock ledges, seepage slopes and the margins of glacial lakes and snowbeds. The specimen from Saniti Lake in Sikkim at about 4250 m in August typifies its preference for cold, moisture-saturated high-altitude turf, where it flowers late in the short growing season as the monsoon wanes and snowmelt keeps the substrate constantly wet.

As its epithet indicates, it is a low perennial herb producing several stems from a stout, often branched rootstock crowned by a rosette of leaves. The basal leaves are obovate to spathulate, entire and narrowed to a petiolar base, forming a compact tuft, while the few stem leaves are small and sessile. The flowers are borne singly or in few-flowered clusters and are typically 4- or 5-merous; the corolla is rotate and deep blue-purple to violet, the lobes ovate-lanceolate and each furnished at the base with one or two fringed nectary scales characteristic of the genus. The stamens alternate with the corolla lobes, and the superior ovary ripens into a many-seeded capsule.

Described by D. Don, Swertia multicaulis is part of the speciose, taxonomically complex Sino-Himalayan radiation of the genus, where species are separated largely by nectary structure, corolla colour and habit. Its cushion-forming, multi-stemmed growth is an adaptation to wind-swept, frost-prone high-alpine conditions. The plant accumulates bitter secoiridoids and xanthones and, like other swertias, has a reputation in local folk medicine. Restricted to intact high-elevation wetland and meadow habitats, it may be vulnerable to grazing and to upward habitat compression under a warming climate.

Author: D. Don · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Hara Enumeration of Flowering Plants of Nepal, Clarke revision of Swertia

Gentianaceae

Swertia nervosa

by GP Jürgens

(G.Don) Wall. ex. C.B.Clarke

Garw 2005 242 ergebnis ergebnis
India Garhwal Bora 2200m, September

Description

Swertia nervosa is an annual gentian-relative widely distributed across the Himalaya and montane Southeast Asia, recorded from China, Nepal, India, Bhutan, Myanmar and Taiwan, with around 331 occurrences in GBIF. It is a plant of moist open slopes, grassy banks, forest clearings, streamsides and disturbed ground in the subtropical to lower temperate belt, typically between 1500 and 2800 m. The photograph from Bora in Garhwal, India, at about 2200 m in September shows it in flower at the close of the monsoon, the period when the genus reaches its peak of flowering across the mid-elevation Himalaya.

The plant is an erect annual herb with an angular, often four-winged or ridged stem branching in the upper part. The leaves are opposite, sessile, lanceolate to ovate-lanceolate and conspicuously several-nerved, the prominent venation reflected in the epithet nervosa. The numerous small flowers are borne in a lax, much-branched terminal panicle; they are usually four-merous with a deeply parted, pale yellowish to greenish corolla often marked with purplish veins, and each lobe bears a fringed nectary gland at its base, a diagnostic feature of Swertia. The fruit is an ovoid bivalved capsule containing many minute seeds.

Swertia is a large genus of the Gentianaceae centred on the Sino-Himalayan region, distinguished by the nectariferous glands (foveae) on the corolla lobes; S. nervosa belongs to the annual, paniculate-flowered group sometimes segregated under Ophelia. Like several relatives it is rich in bitter secoiridoid compounds and is used in traditional medicine as a substitute for the famed chiretta (S. chirayita). Common, weedy and broadly distributed, it is of no conservation concern.

Author: (G.Don) Wall. ex. C.B.Clarke · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Clarke's treatment of Gentianaceae in Flora of British India

Gentianaceae

Swertia pseudohookeri

by GP Jürgens

Harry Sm.

BhutanPG2011 341
Bhutan Jule-Tso, 4000m June

Description

Swertia pseudohookeri is an eastern Himalayan species recorded from Bhutan, Nepal and India, represented in occurrence databases by a modest 17 georeferenced records that reflect both its restricted distribution and its limited collection. It is a plant of high-alpine habitats—moist meadows, open turf, streamsides and the damp margins of glacial lakes—generally near and above 4000 m. The illustrated population at Jule-Tso in Bhutan, photographed at 4000 m in June, typifies its occurrence around tarns and snowmelt flushes where it flowers in the brief alpine summer.

It is an erect annual or short-lived perennial herb with a slender, often quadrangular and sometimes narrowly winged stem arising from a fibrous root. The leaves are opposite, sessile and lanceolate to ovate, with the basal leaves usually larger and the upper ones progressively reduced and bract-like. The inflorescence is a lax, few- to many-flowered cyme; the flowers are typically four- to five-merous with a deeply divided rotate corolla, the lobes pale to bluish or purplish and marked with darker veining, each bearing nectary pits fringed with fimbriae. The fruit is a septicidal, ovoid capsule containing numerous small seeds.

The epithet pseudohookeri, coined by Harry Smith, signals its close morphological resemblance to Swertia hookeri, from which it is distinguished by floral and nectary characters. Swertia is a large, taxonomically intricate genus in the Gentianaceae whose Himalayan members have long been used in traditional medicine for their bitter secoiridoid compounds. Owing to its narrow range and high-elevation niche, S. pseudohookeri is potentially vulnerable to climatic shifts and habitat disturbance, though it has not been formally evaluated.

Author: Harry Sm. · Sources: POWO (Kew), GBIF, Grierson & Long Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Flora of China (Gentianaceae), Harry Smith's monographic studies on Asiatic Swertia

Asteraceae

Symphyotrichum laeve

by GP Jürgens

(L.) Á.Löve & D.Löve

Bhutan2012 1254
Bhutan Trashigang 1720m, October

Description

Symphyotrichum laeve, the smooth blue aster, is native to North America, where GBIF records its overwhelming abundance (15,822 occurrences) across the United States, Canada and Mexico. It is also widely naturalised in Europe (Germany, Netherlands, Sweden, France, Britain, Belgium and beyond) and is recorded as an introduced ornamental elsewhere. In its native range it occupies dry to mesic prairies, open woodland, glades and roadsides. The image was taken at Trashigang in eastern Bhutan at 1720 m in October, where the plant occurs as a cultivated or escaped garden ornamental rather than as a member of the indigenous Himalayan flora.

It is a glabrous, often glaucous perennial herb arising from a short rhizome or caudex, with erect stems to about 1 m. The leaves are alternate, firm and smooth, the lower oblanceolate and tapering to a winged petiole, the upper sessile and clasping with an auriculate base, the margins entire to remotely toothed. The inflorescence is an open paniculiform array of numerous capitula subtended by appressed, imbricate phyllaries with diamond-shaped green tips. Each head bears blue to violet ray florets surrounding yellow disc florets that age to purplish; the achenes are ribbed and crowned by a tawny pappus of capillary bristles.

Formerly placed in Aster, the species was transferred to Symphyotrichum by Á. Löve & D. Löve following molecular evidence dismantling the broad genus Aster, which is now restricted to Old World taxa. Smooth aster is a popular late-season ornamental and pollinator plant. It is secure throughout its native range and behaves as a benign garden escape in temperate regions worldwide.

Author: (L.) Á.Löve & D.Löve · Sources: POWO (Kew), GBIF, Flora of North America, Flora of Bhutan, Symphyotrichum revision (Nesom), Asteraceae of North America