Author

GP Jürgens

Fabaceae

Hedysarum tibeticum

by GP Jürgens

(Benth.) B.H.Choi & H.Ohashi

Sikkim2011 44
Bhutan Chele-La 4000m, May
Sikkim2011 78
Sikkim Vista-valley 3700m, June
Sikkim2011 44 1
Sikkim Vista-valley 3700m, June

Description

Hedysarum tibeticum is a high-alpine legume of the Himalaya and Tibetan plateau, distributed across China, India, Nepal and Bhutan, with around 295 GBIF records; it has historically also been treated under the name Stracheya tibetica, reflecting earlier generic placement. It grows on open stony alpine slopes, gravelly pastures, moraine flats and dry grassy banks near and above treeline, generally between about 3500 and 4500 m. The collections cited from Chele-La in Bhutan at 4000 m in May and from the Vista-valley in Sikkim at 3700 m in June show its early-summer flowering across the high eastern Himalaya.

It is a low, cushion- or mat-forming perennial herb arising from a stout woody rootstock and deep taproot. The leaves are imparipinnate with several pairs of small, oblong to elliptic leaflets that are often appressed-hairy. The flowers are borne in short, dense racemes; each is the typical papilionaceous pea-flower, with a standard, two wings and a keel, coloured pink to purplish-red. The diagnostic fruit is a flattened, transversely jointed lomentum that breaks at maturity into one-seeded segments, the articles often margined or prickly, aiding epizoochorous dispersal.

The taxon has been the subject of nomenclatural revision, the monotypic genus Stracheya having been merged into Hedysarum by Choi and Ohashi on the basis of morphological and molecular evidence, so that POWO now treats Hedysarum tibeticum as accepted. The low cushion habit and deep root are adaptations to wind, cold and the thin soils of the high plateau, while the jointed lomentum is an efficient dispersal device. Widespread across the Tibetan borderlands, the species is not considered threatened and is a characteristic component of high-alpine legume communities.

Author: (Benth.) B.H.Choi & H.Ohashi · Sources: POWO (Kew), GBIF, Flora of China (Fabaceae), Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Choi & Ohashi systematic revision of Hedysarum

Zingiberacaea

Hellenia speciosa

by GP Jürgens

(J.Koenig) Govaerts

Bhutan2012 720
Bhutan Galephu 850m, October

Description

Hellenia speciosa is a robust rhizomatous herb of tropical and subtropical Asia, very widely distributed from India and Sri Lanka through Myanmar, Thailand, Malaysia, Indonesia, the Philippines and southern China to New Guinea and Australia, and widely cultivated and naturalised in the Neotropics and Pacific; its more than 6600 georeferenced records reflect this broad range and horticultural spread. It grows in moist forest understorey, forest margins, stream banks and disturbed ground, generally from near sea level to about 1200 m. The plant photographed at Galephu in southern Bhutan at 850 m in October grows in the warm subtropical foothill forest at the Himalaya's lowland fringe.

It is a tall, leafy herb 1-3 m high with a creeping fleshy rhizome and stout, characteristically spirally twisted leafy stems. The leaves are large, oblong-lanceolate, spirally arranged, with conspicuous sheaths. The inflorescence is a dense terminal cone-like spike of bright red, imbricate bracts from which emerge the showy flowers; each has a large, crinkled, funnel-shaped white labellum with a yellowish centre, subtended by a single fertile stamen with a petaloid filament. The fruit is a globose to ovoid red capsule containing numerous black, arillate seeds.

Formerly placed in Costus as Costus speciosus, the species was transferred to Hellenia by Govaerts; the input labels the family "Zingiberacaea" (Zingiberaceae), retained here verbatim, though the spiral-leaved costaceous gingers are now usually treated as a distinct family. The rhizome, rich in diosgenin, is widely used in traditional medicine and as a steroid precursor. The flowers are bee-pollinated and the bright capsules attract birds. Widespread, weedy and frequently cultivated, H. speciosa is of no conservation concern.

Author: (J.Koenig) Govaerts · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Flora of British India, Specht's monograph of Costus and allied genera (Costaceae)

Orchideaceae

Hemipilia calcicola

by GP Jürgens

(W.W.Sm.) Y.Tang & H.Peng

Sikkim2003 458 P634
Sikkim Chopta Valley 4000m August
Sikkim2003 459 G636
Sikkim Chopta Valley 4000m August

Description

Hemipilia calcicola is a terrestrial orchid of the high Sino-Himalaya, recorded from southwestern China (notably Yunnan and Sichuan) and extending into Nepal, Sikkim and Bhutan, with GBIF logging 199 occurrences across CN, NP and BT. As both its epithet calcicola and its habitat preference indicate, it favours calcareous substrates, growing in alpine and subalpine meadows, on grassy limestone slopes and in open turf, typically between about 3000 and 4300 m. The photographed plant was found in the Chopta Valley of Sikkim at around 4000 m, flowering in August during the late-monsoon alpine flowering season.

The species is a slender terrestrial herb arising from an ovoid or globose underground tuberoid. It typically bears a single basal leaf, ovate to cordate and frequently marked above with purplish spots, clasping the base of the erect flowering stem. The inflorescence is a lax raceme of several resupinate flowers; each has spreading sepals and petals and a prominent, deflexed, often three-lobed labellum bearing a slender nectar-spur at its base. The column carries the pollinaria characteristic of the Orchidaceae, and the fruit is a dehiscent capsule releasing dust-like, abundant seeds requiring mycorrhizal association for germination.

The taxon was originally described as a variety under Habenaria/Neottianthe (reflected in the website slug neottianthe-cucullata-var-calcicola) and was transferred to Hemipilia by Tang and Peng on molecular grounds, consolidating Neottianthe within an expanded Hemipilia. It is one of numerous calciphilous Sino-Himalayan orchids whose specialised soil requirements and dependence on pollinators and mycorrhizae make populations vulnerable to grazing, collection and habitat disturbance.

Author: (W.W.Sm.) Y.Tang & H.Peng · Sources: POWO (Kew), GBIF, Flora of China (Orchidaceae), Genera Orchidacearum (Pridgeon et al.), Tang & Peng revision of Hemipilia

Orchideaceae

Hemipilia chusua

by GP Jürgens

(D.Don) Y.Tang & H.Peng

Sikkim2003 150 P201
Sikkim Dzongri, 4100m August
BhutanPG2011 792
Bhutan Ludlow-Sherriff-Trail Kem-La, 4300m July
BhutanPG2011 677
BhutanPG2011 392
Bhutan Ludlow-Sherriff-Trail Kem-La, 4300m July

Description

Hemipilia chusua is a terrestrial orchid widely distributed across temperate and alpine Asia, recorded from China, Nepal, India, Bhutan, Myanmar, Russia, Japan and Korea, with over 1700 GBIF occurrences making it one of the best-documented orchids of the region. It grows in alpine and subalpine meadow, open turf, grassy slopes and the margins of dwarf-shrub heath, typically between about 2500 and 4500 m. The illustrated plants from Dzongri in Sikkim at 4100 m, flowering in August, and from Kem-La on the Ludlow-Sherriff Trail in Bhutan at 4300 m in July, exemplify its high-altitude grassland habitat.

It is a slender terrestrial herb arising from small ovoid to ellipsoid tubers, with an erect, glabrous stem bearing one or few leaves. The leaves are lanceolate to oblong-lanceolate, sheathing at the base and somewhat clasping the stem. The inflorescence is a lax, few-flowered terminal raceme of showy rosy-purple to magenta flowers; the lip (labellum) is broad, three-lobed and bears a slender, downward-pointing spur longer than the ovary, while the lateral sepals spread and the dorsal sepal and petals form a loose hood. The fruit is an erect, ribbed dehiscent capsule releasing dust-like seeds.

Long familiar as Orchis or Ponerorchis chusua, the species was transferred to Hemipilia by Tang and Peng following molecular reappraisal of the orchidine alliance. Though wide-ranging and locally abundant, like all wild orchids it is listed under CITES Appendix II, and its alpine populations are vulnerable to collection, grazing pressure and the upslope shift of montane vegetation under climate change.

Author: (D.Don) Y.Tang & H.Peng · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Pearce & Cribb The Orchids of Bhutan

Didymocarpinae

Henckelia bifolia

by GP Jürgens

(D.Don) A.Dietr.

Bhutan2015 203
Bhutan Zhemgang 1000m, October

Description

Henckelia bifolia is a Himalayan gesneriad recorded from India, Nepal, Bhutan and Sri Lanka, with about 124 georeferenced occurrences indicating a distribution along the humid southern Himalayan and northeast Indian foothills. It is a plant of warm, shaded, moist habitats: it grows on dripping rock faces, shaded banks, ravines and the floor and margins of subtropical broadleaved forest, generally at lower montane elevations, broadly from about 800 to 1800 m. The illustrated material was gathered at Zhemgang in Bhutan at 1000 m in October, a low, humid forested setting typical of the species, which flowers toward the close of the monsoon season.

It is a small perennial herb, often nearly stemless, with the leaves few and basal; as the epithet bifolia implies, the plant frequently develops a pair of opposite, sometimes markedly unequal leaves that are ovate, soft-textured, crenate to toothed and pubescent. The flowers are borne on slender axillary peduncles in few-flowered cymes; the corolla is zygomorphic, tubular and bilabiate, pale violet to bluish-lilac, with a short erect upper lip and a larger spreading three-lobed lower lip. Two stamens are fertile, and the superior ovary matures into the straight, narrowly cylindrical capsule diagnostic of Henckelia.

Henckelia (Gesneriaceae) was recircumscribed in the molecular reclassification of the didymocarpoid gesneriads, absorbing many species previously placed in Didymocarpus and Chirita; the name listed here as the family, Didymocarpinae, is in fact the subtribe to which Henckelia belongs, and the species properly sits in Gesneriaceae. The genus is characterised by its straight undivided capsules and bilabiate flowers. As a humid-forest understorey herb of restricted, fragmented habitats, H. bifolia depends on intact low-montane forest, and although not formally assessed it is potentially vulnerable to deforestation.

Author: (D.Don) A.Dietr. · Sources: POWO (Kew), GBIF, Flora of Bhutan, A Revised Handbook to the Flora of Ceylon, Weber & Möller revision of Henckelia (Gesneriaceae)

Didymocarpinae

Henckelia calva

by GP Jürgens

(C.B.Clarke) D.J. Middleton & Mich. Müller

Sikkim2003 59 P79
Sikkim above Yoksam 2750m August
Sikkim2003 60 G80
Sikkim Yoksam 1800m, August

Description

Henckelia calva (C.B.Clarke) D.J.Middleton & Mich.Müller is a perennial herb of the Gesneriaceae (the input subtribe name Didymocarpinae notwithstanding), distributed across the eastern Himalaya and adjacent ranges. GBIF (a sparse 12 occurrences) records it from northern India, Bhutan and Myanmar, where it grows on shaded, moss-covered rocks, damp banks and forest understorey in humid broad-leaved and evergreen forest. The two Sikkim records at Yoksam, at 1,800 m and 2,750 m, both in August during the monsoon, indicate a montane preference broadly between 1,500 and 3,000 m, where high atmospheric humidity supports its growth.

The plant is a soft, more or less rhizomatous herb. Leaves are opposite, ovate to elliptic, often somewhat fleshy, with a crenate to serrate margin and a relatively sparse indumentum (the epithet "calva", meaning bald or glabrescent, alludes to this comparatively smooth surface). The inflorescences are axillary cymes bearing showy zygomorphic flowers; the corolla is tubular and bilabiate, white to pale violet or bluish, the throat sometimes marked with yellow. There are two fertile stamens with cohering anthers, and the ovary is superior, maturing into the elongate, narrowly cylindrical, twisted capsule characteristic of Henckelia, which splits to release numerous minute seeds.

The species was transferred from Didymocarpus to a recircumscribed Henckelia following molecular phylogenetic studies of Old World Gesneriaceae by Middleton, Möller and collaborators, a reclassification that reshaped generic limits in the subtribe Didymocarpinae. As a narrow-range, hygrophilous understorey herb of the eastern Himalaya, it is intrinsically vulnerable to forest disturbance and habitat loss, and its few documented occurrences underline the need for continued field survey of the region's Gesneriaceae.

Author: (C.B.Clarke) D.J. Middleton & Mich. Müller · Sources: POWO (Kew), Flora of Bhutan Vol. 2, Flora of China Vol. 18, GBIF, Weber & Burtt: Remarks on the classification of Gesneriaceae

Didymocarpinae

Henckelia pumila

by GP Jürgens

D.Don A.Dietr.

Sikkim2003 23 G27
Sikkim Rathong-Chu 1200m, August
Garw 2005 214 ergebnis ergebnis
India Garhwal Simkarok 2680m, September
Bhutan2015 89
Bhutan Galephug 600m, October

Description

Henckelia pumila is a small gesneriad of the eastern and central Himalaya and adjacent Indo-Burma, recorded from China, India, Nepal, Myanmar, Bhutan, Thailand and Vietnam, with close to 600 occurrences in GBIF. It is a plant of shaded, humid habitats, growing on moist rock faces, mossy boulders, stream banks and shaded earth cuttings within evergreen broad-leaved and subtropical hill forest. Its wide altitudinal amplitude is reflected in the collection localities given for the illustrated material, ranging from the Rathong Chu in Sikkim at 1200 m in August and Galephug in Bhutan at only 600 m in October up to Simkarok in Indian Garhwal at 2680 m in September, indicating tolerance of both warm subtropical and cool temperate forest understorey.

The plant is a small perennial or facultatively annual herb with a short, often weak stem and crowded, opposite or subopposite leaves that are ovate to elliptic, crenate-serrate and softly hairy, frequently somewhat fleshy and unequal in a pair. The flowers are borne singly or in few-flowered cymes on slender peduncles from the leaf axils. The corolla is tubular and weakly two-lipped, white to pale lilac or bluish, often with a yellow throat or coloured markings, with the lower lip the more spreading. There are two fertile stamens with coherent anthers, and the ovary is superior, developing into the slender, elongate, twisted or straight loculicidal capsule typical of the genus.

The family is given as Didymocarpinae on the source page, the subtribal name within the Gesneriaceae to which Henckelia belongs; the species is correctly a member of the Gesneriaceae. The genus Henckelia has been substantially recircumscribed following molecular study, with numerous Asiatic didymocarpoid species transferred into and out of it, and H. pumila sits within this Sino-Himalayan radiation of rock-dwelling gesneriads. Its capacity to colonise moist shaded rock and its broad elevational range make it locally frequent, and it is not regarded as threatened.

Author: D.Don A.Dietr. · Sources: POWO (Kew), GBIF, Flora of China Vol. 18, Flora of Bhutan Vol. 2, Flora of Nepal, A Revision of the Genus Henckelia (Gesneriaceae)

Didymocarpinae

Henckelia urticifolia

by GP Jürgens

(Buch.-Ham. ex D.Don) A.Dietr

Bhutan2012 646
Bhutan Tserang 1600m, September
Sikkim2003 348 W489
Sikkim above Yoksam 1880m August

Description

Henckelia urticifolia is a Himalayan gesneriad ranging through Nepal, China, India, Bhutan and Myanmar, the c. 212 georeferenced records concentrated along the humid southern Himalayan front. It is a plant of shaded, moist understorey habitats: it grows on damp banks, mossy rock faces, ravines and the margins of broadleaved and subtropical forest, generally between about 1200 and 2200 m. The illustrated material was gathered at Tserang in Bhutan at 1600 m in September and above Yoksam in Sikkim at 1880 m in August, locations typical of its preference for cool, dripping, sheltered sites that retain monsoon moisture.

It is a perennial herb with an erect to ascending, often softly hairy stem. As the epithet suggests, the leaves are nettle-like (urticifolia): opposite, ovate, coarsely toothed, thin-textured and pubescent, with prominent venation. The flowers are borne in axillary cymes; the calyx is five-parted and the corolla zygomorphic, tubular and bilabiate with a short two-lobed upper lip and a larger spreading three-lobed lower lip, pale violet to bluish-mauve, often with darker guidelines and a paler throat. There are two fertile stamens with cohering anthers, and the ovary is superior. The fruit is the characteristic elongate, narrowly cylindrical capsule of the genus.

Henckelia (Gesneriaceae) was recircumscribed in the molecular reclassification of the Old World didymocarpoid gesneriads, with many Asiatic species formerly placed in Didymocarpus and Chirita transferred to it; the supra-generic placement in subtribe Didymocarpinae reflects that scheme, so the family name given here, though listed as the subtribal name, properly resolves to Gesneriaceae. The genus is defined by its straight, undivided capsules and bilabiate corolla. Forest-dwelling and locally common, the species is not presently considered threatened, but it depends on intact humid forest cover.

Author: (Buch.-Ham. ex D.Don) A.Dietr · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Weber & Möller revision of Henckelia (Gesneriaceae)

Araliaceae

Heptapleurum digitatum

by GP Jürgens

(G.Don ex Loudon) Lowry & G.M.Plunkett

Bhutan2014 71
Bhutan Trashigang 1350m, May

Description

Heptapleurum digitatum is an Indo-Himalayan and Indo-Malesian tree distributed from the eastern Himalaya through northeastern India, Bangladesh, Myanmar and Thailand into the Malesian region, with GBIF recording around 116 occurrences across India, Bhutan, Nepal, Bangladesh, Myanmar, Thailand, Indonesia and Malaysia. It is a plant of warm subtropical to lower montane broadleaf forest, occurring in the foothill belt; the illustrated material comes from Trashigang in eastern Bhutan at 1350 m, flowering in May. It favours humid, evergreen and semi-evergreen forest, ravine slopes and stream banks, where it grows as an understorey to canopy tree, sometimes epiphytic or hemi-epiphytic when young.

The species is a small to medium-sized evergreen tree with stout, often sparsely branched stems bearing conspicuous leaf scars. The leaves are large, alternate, long-petiolate and digitately (palmately) compound, with several to many oblong-elliptic, entire, glabrous, coriaceous leaflets radiating from the petiole apex, the whole giving the characteristic umbrella-plant silhouette of the genus. The numerous small flowers are five-merous, with minute petals and an inferior ovary, arranged in umbellules grouped into large, much-branched terminal panicles. The fruit is a small, subglobose, slightly ribbed drupe with several pyrenes, attractive to birds.

The combination (G.Don ex Loudon) Lowry & G.M.Plunkett reflects the segregation of the Asian "Schefflera" lineages, this species having long been treated under Schefflera. Heptapleurum sensu stricto is now recognised as a large palaeotropical genus within Araliaceae. Widespread and frequent in suitable forest, the species is not considered threatened, and its bird-dispersed drupes and accessible nectar make it an important resource in subtropical forest food webs.

Author: (G.Don ex Loudon) Lowry & G.M.Plunkett · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Flora of British India (Hooker), Lowry & Plunkett revision of Schefflera/Heptapleurum (Araliaceae), Frodin & Govaerts World Checklist of Araliaceae

Apiaceae

Heracleum candidans var. obtusifolium

by GP Jürgens

(Wall. ex DC.) F.T.Pu & M.F.Watson

BhutanPG2011 769 01 01
Bhutan Chele-La, 3900m July

Description

Heracleum candidans var. obtusifolium (Wall. ex DC.) F.T.Pu & M.F.Watson is treated by GBIF as a synonym, with the accepted name being Heracleum candicans obtusifolium. It is a Himalayan umbellifer recorded from China and Nepal, GBIF documenting 44 occurrences, and is a plant of the upper subalpine and alpine zones. It occupies open slopes, meadow flushes, shrubberies and forest clearings, typically between about 3000 and 4200 m. The photographed plant at the Chele-La in western Bhutan, at roughly 3900 m in July, illustrates its association with the moist, high-elevation grasslands of the eastern Himalaya during the summer flowering season.

The plant is a robust, tomentose perennial with a stout rootstock and erect, ridged, hollow stems. The leaves are large and pinnately divided, with broad, lobed segments that are densely white-woolly beneath, the obtuse leaf segments giving the variety its epithet. The inflorescence is a large compound umbel with numerous rays subtended by deciduous bracts; the small flowers are white, with the marginal flowers often radiant and the outer petals enlarged and bilobed. The fruit is a dorsally compressed, broadly winged schizocarp bearing conspicuous oil ducts (vittae), the typical mericarp of the genus.

Heracleum is a taxonomically difficult genus in the Himalaya, with a continuum of closely allied entities; this taxon has been variously ranked as a species, subspecies or variety, and its placement under H. candicans reflects ongoing molecular and morphological reassessment of the group. As with other species of the genus, the foliage and sap contain furanocoumarins that may cause phototoxic dermatitis. The taxon is not regarded as threatened, though it occupies the narrow, climate-sensitive alpine belt of the central and eastern Himalaya.

Author: (Wall. ex DC.) F.T.Pu & M.F.Watson · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora of Nepal, Pimenov & Leonov genera of Umbelliferae