Author

GP Jürgens

Asteraceae

Ajania nubigena

by GP Jürgens

(Wall. ex DC.) Muldashev

Bhutan2012 303
Bhutan Shale-La, 4300m September
Garw 2005 301 ergebnis scaled
Garw 2005 302 ergebnis scaled
India Garhwal Patanathi 3600m, September

Description

Ajania nubigena is a high-altitude aromatic composite of the Himalaya and Tibetan borderlands, recorded from Nepal, China (Tibet), India and Bhutan, with 266 georeferenced occurrences spanning the alpine zone of the main range. It grows on dry, stony alpine slopes, gravelly screes, rock crevices and exposed ridges, typically in the upper subalpine to alpine belt. It was photographed on the Shale-La in Bhutan at 4300 m and in Garhwal, India, at Patanathi at 3600 m, both in September, when its yellow heads flower amid the dry autumn alpine turf of these high passes.

It is a low, tufted, somewhat woody-based perennial subshrub or herb forming compact clumps, the stems and foliage clothed in dense grey to silvery appressed hairs that give a felted appearance and impart drought and frost tolerance. The leaves are small, alternate and pinnately or bipinnately dissected into narrow lobes, grey-tomentose especially beneath. The flower heads are small, discoid (lacking ray florets) and yellow, aggregated into dense terminal corymbs; each head has an involucre of imbricate, scarious-margined phyllaries and numerous tubular hermaphrodite and marginal female florets. The fruit is a small ribbed cypsela, usually lacking a pappus.

The genus Ajania, segregated from Chrysanthemum and Tanacetum within tribe Anthemideae, comprises mostly silvery-leaved, discoid-headed species of arid Central Asian and Himalayan uplands; the combination (Wall. ex DC.) Muldashev reflects this transfer. Its dense indumentum and dissected leaves are adaptations to the cold, dry, high-radiation alpine environment. Ecologically it is a xerophytic specialist of open stony ground, widespread within its altitudinal band and of no conservation concern.

Author: (Wall. ex DC.) Muldashev · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Anthemideae systematics (Bremer & Humphries monograph)

Fabaceae

Albizia julibrissin

by GP Jürgens

Durazz.

Bhutan2014 696
Bhutan Wangdi Phodrang 2000m, May
Bhutan2014 699
Bhutan Wangdi Phodrang 2000m, May

Description

Albizia julibrissin, the silk tree or Persian silk tree, is a deciduous tree native from Iran and the Caucasus across to eastern Asia, now extensively planted and naturalised worldwide as shown by GBIF's more than 35000 occurrences spanning the United States, Korea, Japan, China, France, Turkey, Russia, Argentina, Italy and India among many others. In its Asian range it grows in warm-temperate broadleaf forest, open hillsides, valley margins and disturbed roadsides, from the lowlands to about 2500 m. The photographed tree from Wangdi Phodrang in Bhutan at 2000 m in May represents its occurrence in the warm inner Himalayan valleys, where it flowers in late spring and through the warm season.

It is a small, spreading tree with a broad, flat-topped, umbrella-like crown and smooth greenish-grey bark. The large, alternate leaves are bipinnate with numerous pinnae each bearing many small, oblong, asymmetric leaflets that fold together at night. The inflorescences are dense, hemispherical heads grouped in terminal panicles; the flowers are inconspicuous in their corollas but conspicuous through their numerous long, silky stamens, pink to deep rose distally and white below, giving a powder-puff effect. The fruit is a flat, papery, straw-coloured dehiscent legume containing several flattened seeds.

Albizia belongs to Fabaceae subfamily Caesalpinioideae (the mimosoid clade), characterised by actinomorphic flowers with showy stamens far exceeding the small petals. Nitrogen-fixing through root nodulation, fast-growing and widely cultivated as an ornamental, it has become invasive in parts of North America and elsewhere. Globally of Least Concern, it is valued horticulturally and ecologically as a pioneer of disturbed, well-drained, sunny sites.

Author: Durazz. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora Iranica, Nielsen revision of Albizia and allied Mimosoideae

Fabaceae

Albizia lebbeck

by GP Jürgens

(L.) Benth.

Bhutan2014 238
Bhutan Karu-Chu 1800m, May
Bhutan2014 240
Bhutan Karu-Chu 1800m, May

Description

Albizia lebbeck is a fast-growing tropical tree native to the Indian subcontinent and tropical Asia but now pantropically naturalised, as its 13,114 GBIF occurrences from India, Australia, Brazil, Mexico, the United States, Madagascar, Nigeria and many other countries attest. It occupies open woodland, savanna, riverbanks, roadsides and disturbed ground from the lowlands to about 1800 m, and is widely planted for shade, timber and fodder. The photographed tree was recorded in Bhutan along the Karu-Chu at about 1800 m in May, near the upper limit of its altitudinal range in the warm Himalayan foothills.

It is a deciduous tree to 15-25 m with a spreading, flat-topped crown and grey, fissured bark. The leaves are bipinnate with 2-4 pairs of pinnae, each bearing 4-9 pairs of oblong, asymmetric leaflets, and a conspicuous gland on the petiole. The flowers are massed in showy, hemispherical axillary heads, each flower with a small calyx and corolla but numerous long, greenish-white to cream stamens fused below into a tube, giving a powder-puff appearance and a sweet fragrance. The fruit is a flat, straw-coloured, papery legume 15-30 cm long, persisting on the tree and rattling in the wind, containing several flattened seeds.

A member of the Fabaceae (subfamily Caesalpinioideae, mimosoid clade), Albizia lebbeck fixes nitrogen through root nodules and is valued in agroforestry, though it behaves as an invasive weed in parts of the Neotropics, Australia and Pacific islands. Pollination is by insects and birds attracted to the nectar-rich stamen brushes, and the buoyant pods aid wind and water dispersal. It is of least concern and globally abundant.

Author: (L.) Benth. · Sources: POWO (Kew), GBIF, Flora of British India, Flora of Bhutan, Nielsen Monograph of Asian Albizia

Fabaceae

Albizia sherriffii

by GP Jürgens

Baker f.

Bhutan2014 3
Bhutan Sandrup 750m, May
Bhutan2014 5
Bhutan Sandrup 750m, May
Bhutan2014 224
Bhutan Karu-Chu 1800m, May
Bhutan2014 229
Bhutan Karu-Chu 1800m, May

Description

Albizia sherriffii is a tree of the eastern Himalayan foothills and adjoining ranges, recorded from Bhutan, north-east India, Myanmar and southern China, with GBIF holding about 65 occurrences that indicate a fairly restricted distribution. It occurs in warm subtropical to lower-temperate broad-leaved forest and along forest margins and river valleys, broadly between 700 and 1800 m, where the monsoon climate is warm and humid. The two illustrated Bhutanese gatherings, from Sandrup at 750 m and Karu-Chu at 1800 m, both in May, bracket its elevational range and show its flowering at the onset of the rains.

It is a medium-sized to large deciduous tree with spreading branches and bipinnate leaves bearing several pairs of pinnae, each with numerous small, oblong leaflets, the foliage often subtended by a gland on the petiole as is characteristic of the genus. The flowers are grouped in capitate or umbellate heads and, as in Albizia generally, owe their showy appearance to the long, numerous, exserted stamens united below into a tube, the small corolla being inconspicuous. The fruit is a flat, oblong, dehiscent legume (pod) containing several compressed seeds.

Named for the plant collector George Sherriff, A. sherriffii belongs to the mimosoid legumes (Fabaceae subfamily Caesalpinioideae, mimosoid clade), within which Albizia is distinguished from Acacia and allied genera by its stamen and pod characters. As a relatively narrowly distributed Himalayan tree, it is potentially sensitive to lowland forest clearance, though it has not been formally assessed in detail.

Author: Baker f. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Legumes of the World (Lewis et al.), Flora of China

Nartheciaceae

Aletris glabra

by GP Jürgens

Bureau & Franch.

Sikkim2011 29
Sikkim Lachen 2760m, June

Description

Aletris glabra is a rosette-forming perennial herb of the Nartheciaceae, distributed across the eastern Himalaya and East Asia. GBIF data (nearly 1,300 occurrences) confirm a native range spanning China, Taiwan, Korea, Japan, the Korean peninsula, India, Nepal and Bhutan. The species grows in moist, open habitats including subalpine and alpine meadows, grassy slopes, marshy ground, bog margins and forest clearings, typically in the temperate to subalpine belt. The collection from Lachen in northern Sikkim at 2,760 m in June reflects its occurrence in damp montane grassland and meadow flushes in the early summer flowering season.

The plant forms a basal rosette of narrowly lanceolate to linear, soft, grass-like leaves. From the centre arises a slender, erect flowering scape bearing a narrow, elongate raceme of small flowers. The flowers are campanulate to narrowly tubular, white to greenish-white, with six perianth lobes united below into a tube; unlike the mealy or warty-flowered relatives, the perianth of A. glabra is comparatively smooth, the epithet glabra denoting this glabrous character. There are six stamens inserted on the tube, and a superior to half-inferior, three-locular ovary. The fruit is a small, ovoid to ellipsoid loculicidal capsule containing numerous minute seeds.

The genus Aletris was long placed in the Liliaceae or Melanthiaceae but is now referred, with Narthecium, to the small monocot family Nartheciaceae within the Dioscoreales. The group is of phylogenetic interest as an early-diverging lineage of the order. As a plant of wet meadows and bog margins, A. glabra is an indicator of intact damp grassland; though widely distributed and secure overall, such wetland habitats are locally threatened by drainage and grazing.

Author: Bureau & Franch. · Sources: POWO (Kew), Flora of China Vol. 24, Flora of Bhutan Vol. 3, GBIF, Tamura: The Families and Genera of Vascular Plants – Nartheciaceae

Asteraceae

Allardia glabra

by GP Jürgens

Decne.

Sikkim2003 518 G720
Sikkim Yume Samdong 4700m August
Sikkim2003 519 P724
Sikkim Yume Samdong 4700m August

Description

Allardia glabra is a high-alpine composite of the Himalaya and central Asia, distributed across Nepal, India, China, Pakistan, Tajikistan, Bhutan, Afghanistan and Kazakhstan, with GBIF documenting about 327 occurrences. It is a plant of the uppermost alpine and subnival zones, growing on screes, moraines, gravelly flats and stony slopes at very high elevations, commonly between about 4000 and 5500 m. The photographed material from Yume Samdong in northern Sikkim at 4700 m, flowering in August, is typical of its extreme habitat, where it forms low cushions or mats on bare, frost-disturbed ground near the limit of vascular plant life, taking advantage of the short, intense growing season of the high summer.

It is a dwarf, cushion- or mat-forming perennial arising from a branched, often stout caudex clothed in the persistent remains of old leaves. The leaves are small, crowded, spathulate to obovate and entire or shallowly lobed at the tip, and, as the epithet glabra indicates, relatively glabrous compared with the woolly indumentum of related species. The flower heads are solitary, sessile or shortly stalked, nestled among the foliage, and radiate, with an involucre of imbricate, often dark-margined bracts. The pistillate ray florets are pink to lilac or whitish, surrounding numerous yellow tubular disc florets. The fruit is a small, ribbed cypsela crowned by a short pappus.

Allardia is a small genus of about half a dozen species centred on the high mountains of central Asia and the Himalaya, long included within Waldheimia, under which name (Waldheimia glabra) this taxon is frequently encountered. Its cushion habit, reduced glabrous leaves and ground-hugging capitula are classic adaptations to cold, wind-exposed, high-radiation subnival environments. As a specialist of the highest vegetated ground it is of biogeographic interest and potentially sensitive to upward shifts of the climatic snowline, though its remoteness affords protection.

Author: Decne. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Pakistan, Annotated Checklist of the Flowering Plants of Nepal, Podlech and Asteraceae monographic treatments of Allardia (Waldheimia)

Amaryllidaceae

Allium prattii

by GP Jürgens

C.H.Wright

Sikkim2003 206 P288
Sikkim Dzongri 4000m, August

Description

Allium prattii is a widespread alpine onion of the Himalaya and adjacent ranges, distributed across China, Nepal, Bhutan, India, Afghanistan, Myanmar and Mongolia, and is among the better-documented species in this set with nearly 1500 georeferenced records in GBIF. It grows in subalpine and alpine meadows, forest clearings, scrub and damp grassy slopes, generally between about 2500 and 4500 m. The plant illustrated was photographed at Dzongri in Sikkim at 4000 m in August, a characteristic high-alpine setting where it flowers during the summer monsoon.

The species is a bulbous perennial with a narrowly cylindrical to ovoid bulb sheathed in fibrous to membranous tunics. It typically bears two flat, lanceolate to elliptic basal leaves that are shorter than to about equalling the scape. The leafless flowering stem is erect and terete, bearing a terminal, more or less hemispherical umbel subtended by a persistent papery spathe. The flowers are stellate to campanulate, with six purplish-red, rose to lilac tepals, exserted stamens and a superior ovary; the fruit is a small loculicidal capsule containing black seeds.

Allium prattii is placed in Allium (Amaryllidaceae, subfamily Allioideae), a very large genus whose Himalayan and Central Asian members form a notable centre of diversity. Like several relatives it is edible, gathered locally as a wild vegetable and seasoning, and grazed by livestock. Its broad geographic and altitudinal range and large population base make it secure overall, and it is not regarded as threatened, though particular alpine stands are subject to heavy collection and grazing pressure in well-frequented high-pasture areas.

Author: C.H.Wright · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Stearn Monograph of the Genus Allium

Alliaceae

Allium wallichii

by GP Jürgens

Kunth

Bhutan2012 30
Bhutan Chele-La 3400m, September

Description

Allium wallichii is a Himalayan and Sino-Himalayan onion widely distributed through SW China, Nepal, NE India, Bhutan, Myanmar and Pakistan, GBIF recording around 1,300 occurrences (with cultivated records reaching Europe). It is a plant of the subalpine and alpine zone, growing in open meadows, grassy slopes, forest clearings and damp pastures, generally between about 2,300 and 4,800 m. The photographed plant from Chele-La in western Bhutan at 3,400 m (September) is characteristic, flowering in the late-monsoon period when the high meadows are at their richest.

It is a perennial herb arising from a slender, oblique rhizome bearing a poorly developed, narrowly conic bulb. The leaves are basal, several, narrowly linear to lorate and flat or shallowly keeled, sheathing the lower part of the triangular or angled scape. The inflorescence is a terminal, many-flowered umbel that is hemispherical to globose and lacks bulbils; the flowers are stellate, with six spreading purple to reddish-purple (rarely whitish) tepals, exserted stamens and a superior ovary. The fruit is a small loculicidal capsule.

The family is given verbatim as Alliaceae, the segregate now generally subsumed within Amaryllidaceae subfamily Allioideae. Allium wallichii is gathered as a wild vegetable and flavouring (jimbu and related condiments) across the Himalaya and is used medicinally, which together with grazing places local pressure on accessible populations. The species is morphologically variable across its wide range, and its rhizomatous, non-bulbous habit and flat leaves distinguish it within the alpine Himalayan alliums; it is not currently regarded as globally threatened.

Author: Kunth · Sources: POWO (Kew), Flora of Bhutan Vol. 2, GBIF, Flora of China Vol. 24, Stearn: The Genus Allium in the Himalaya

Betulaceae

Alnus nepalensis

by GP Jürgens

D.Don

Bhutan2012 1150
Bhutan Tashiyangtse 1750m, October
Nepal 1994 159 ergebnis
Ost-Nepal Mewa-Khola
1800m, April

Description

Alnus nepalensis D.Don, the Nepalese alder, is a deciduous tree of the Betulaceae distributed throughout the Himalaya and adjacent ranges, from Nepal and India through Bhutan to southwestern China, Myanmar and Vietnam (GBIF: c. 1,931 occurrences). It is a fast-growing pioneer of moist temperate and subtropical zones, colonising landslides, river terraces, abandoned fields and forest gaps, typically between about 900 and 2,700 m. The photographed trees from Tashiyangtse in eastern Bhutan (c. 1,750 m) and the Mewa-Khola in eastern Nepal (c. 1,800 m) exemplify its dominance on moist, disturbed mid-montane slopes.

The tree reaches 10–25 m, with smooth grey bark becoming fissured with age. The leaves are alternate, broadly elliptic to ovate, acuminate, with finely serrate to nearly entire margins and prominent pinnate venation. Unusually for the genus, A. nepalensis flowers in autumn: the slender pendulous male catkins and short erect female inflorescences appear together, and the female structures mature into small, woody, cone-like infructescences (strobiles) that persist on the tree and release tiny winged nutlets (samaras) for wind dispersal.

Alnus nepalensis is ecologically and economically significant as a nitrogen-fixing species, harbouring symbiotic actinomycetes of the genus Frankia in root nodules; this enables it to enrich degraded soils, making it valuable in agroforestry, soil reclamation, watershed restoration and as a shade tree in cardamom cultivation. The wood is used for timber, fuel and matchwood. The species is abundant and of least conservation concern.

Author: D.Don · Sources: POWO (Kew), Flora of China Vol. 4, Flora of Bhutan Vol. 1, Flora of Nepal, GBIF, Chen & Li: Betulaceae of China

Apocynaceae

Alstonia neriifolia

by GP Jürgens

D.Don

Nepal 97 45 G67
Nepal Mewa-Khola 1100m, April
Nepal 97 46 P68
Nepal Mewa-Khola 1100m, April

Description

Alstonia neriifolia is a shrub or small tree of the warm, humid lower hills of the eastern Himalaya and Indo-Burmese region, recorded from India, Nepal, Bhutan, China and southwards into mainland and insular Southeast Asia including Vietnam, Indonesia and Singapore. It occupies subtropical broad-leaved forest, forest margins, stream banks and shaded ravines at low to moderate elevations. The specimen photographed at Mewa-Khola in eastern Nepal at 1100 m in April reflects its preference for the warm, moist foothill belt, where it flowers as the pre-monsoon temperatures rise.

Like other members of its genus it exudes a white latex when cut. The leaves are arranged in whorls of three or more, narrowly lanceolate to oblong and acuminate, recalling those of Nerium (oleander) and giving the species its epithet; the lamina is glabrous and leathery with numerous closely parallel lateral veins running to a marginal collecting vein. The flowers are borne in terminal cymose clusters, with a small five-lobed calyx and a salverform white to cream corolla whose lobes overlap to the left in bud. The fruit is a pair of slender, elongate follicles that split to release numerous flattened seeds bearing tufts of hairs at both ends for wind dispersal.

Alstonia is a pantropical genus of the Apocynaceae, subfamily Rauvolfioideae, well known for the indole alkaloids in its bark, several species of which are valued in traditional medicine and as timber. Alstonia neriifolia, described by D.Don, is distinguished from the better-known A. scholaris by its narrower, oleander-like leaves and smaller stature. Its comma-shaped, comose seeds and reliance on insect pollination of the fragrant flowers underpin its ecology in disturbed and successional foothill forest.

Author: D.Don · Sources: POWO (Kew), GBIF, Flora of China, Annotated Checklist of the Flowering Plants of Nepal, Flora of Bhutan, Middleton's revision of Asian Alstonia (Apocynaceae)