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Summer

Rosaceae

Potentilla polyphylla

by GP Jürgens

Schur

BhutanPG2011 396
Bhutan Tsochenchen, 3550m June
D444371527264B45943B2C738598F852 1
Bhutan Dur-Tso-Chu, 3500m June

Description

Potentilla polyphylla is a Himalayan and Sino-Himalayan cinquefoil ranging through Nepal, north-east India, Bhutan, south-west China, Myanmar, Afghanistan and Pakistan, with 340 georeferenced occurrences. It is a plant of open alpine and subalpine habitats, occupying grassy slopes, meadows, rocky banks, stream margins and the moist turf around glacial lakes. The Bhutan collections at Tsochenchen (3550 m) and Dur-Tso-Chu (3500 m), both in June, place it firmly in the high-alpine zone, typically between about 3000 and 4300 m. GBIF treats the supplied name as a synonym while retaining Potentilla polyphylla as the accepted name; it has at times been confused with Potentilla leuconota.

It is a perennial herb arising from a stout, woody rootstock, producing tufted basal leaves and ascending flowering stems. The leaves are pinnately compound (interrupted-pinnate) with numerous small, closely set, oblong-obovate leaflets that are sharply toothed and silky-hairy, especially beneath. The flowers are borne in lax terminal cymes; each has five green sepals alternating with an epicalyx, five rounded yellow petals, numerous stamens, and many free carpels seated on a hairy receptacle. The fruit is a cluster of small dry achenes.

Within the large genus Potentilla the species sits among the pinnate-leaved high-mountain cinquefoils, a taxonomically intricate group where leaf division and indumentum provide key diagnostic characters. The open yellow flowers are pollinated by a variety of alpine insects. Widely distributed across the Himalayan arc and tolerant of grazed pasture, it is not regarded as threatened, and like other alpine Potentilla species it has local ethnobotanical uses.

Author: Schur · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Flora of Nepal, Soják Potentilla taxonomic revisions

Rosaceae

Potentilla reptans

by GP Jürgens

L.

Sikkim2003 475 G660
Sikkim Lachung Valley 3200m August

Description

Potentilla reptans, creeping cinquefoil, is an exceptionally widespread Eurasian and North African perennial, one of the commonest of all temperate herbs, with over 740,000 GBIF occurrences dominated by European records from France, Britain, the Netherlands, Germany, Scandinavia, Iberia and Russia, alongside its introduced range. It thrives in grassland, roadsides, meadows, lawns and disturbed moist ground from lowlands to montane elevations. In the Himalaya it occurs as a native or naturalised element, as documented in the Lachung Valley of Sikkim at 3200 m in August, where it grows along damp valley tracks and pasture edges during the monsoon.

It is a prostrate, stoloniferous perennial spreading by long slender runners that root at the nodes to form extensive mats. The leaves are long-petioled and palmately compound, usually with five obovate, coarsely toothed leaflets (hence "cinquefoil"), green and sparsely hairy. The flowers are solitary on slender axillary pedicels arising from the nodes, the corolla bright yellow with five broadly obcordate petals exceeding the epicalyx and calyx, surrounding numerous stamens and a dome of free carpels on a hairy receptacle. The fruit is an aggregate of small, dry, finely rugose achenes.

Potentilla is a large rosaceous genus and P. reptans is a model of clonal growth, reproducing efficiently by rooting stolons as well as by seed. Its open yellow flowers are visited by a broad range of generalist insects. As an aggressive colonist of disturbed ground it is of weedy rather than conservation significance and is among the most ecologically successful species in the genus.

Author: L. · Sources: POWO (Kew), GBIF, Flora Europaea, Flora of China, Flora of British India, Wolf monograph of Potentilla

Rosaceae

Potentilla saundersiana var. caespitosa

by GP Jürgens

(Wolf) Soják

Bh2008 595 P890
Bhutan Chele-La, 3950m June

Description

A high-alpine cushion-forming herb of the central and eastern Himalaya and the Tibetan Plateau, recorded across China, Nepal, India and Pakistan, with some 175 georeferenced GBIF occurrences. It occupies dry, open alpine turf, gravelly slopes, rocky ledges and exposed ridge crests, typically between about 3500 and 5000 m. The depicted plant was photographed in June on the Chele-La in western Bhutan at roughly 3950 m, a windswept pass habitat where dwarfed, mat-forming growth is favoured under intense insolation, cold nights and a short summer growing season.

The taxon forms dense, low caespitose tufts arising from a thick, branched, often woody-based rootstock crowned with marcescent stipules and leaf remnants. The leaves are digitate (palmate), with three to five obovate, deeply incised-serrate leaflets that are green and sparsely strigose above and densely white-tomentose beneath, the indumentum giving the foliage a silvery cast. Slender, ascending cymes bear few yellow flowers; each has five sepals alternating with smaller epicalyx segments, five obcordate golden petals slightly exceeding the calyx, numerous stamens and an apocarpous gynoecium of many free carpels. The fruit is a cluster of small, glabrous, smooth to faintly rugose achenes.

GBIF treats the name as a synonym, with Potentilla saundersiana caespitosa accepted; the variety represents a compact, densely tufted high-elevation expression of the widespread, polymorphic P. saundersiana complex. The species is one of many silvery alpine cinquefoils whose infraspecific limits remain debated. Ecologically it stabilises thin alpine soils and provides nectar to short-season pollinators. Though local populations are restricted to specialised habitats, the broad geographic range and abundance of suitable terrain mean it is not regarded as threatened.

Author: (Wolf) Soják · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Soják revisions of Potentilla

Rosaceae

Potentilla saundersiana var. jaquemontii

by GP Jürgens

Franch.

BhutanPG2011 236
Bhutan Tsochenchen, 3700m June
Also included: Calathodes palmata Hook.f. & Thomson

Description

Potentilla saundersiana (the variety jaquemontii here referred to it) is a cushion-forming cinquefoil of the high mountains of Central Asia and the Himalaya, ranging through China, Nepal, India, Bhutan and Pakistan, with GBIF recording over 1000 occurrences; the European points from Germany, France and Sweden reflect herbarium and cultivated material. It is a plant of stony alpine meadows, gravelly slopes, rock crevices and dry pastures in the alpine and subnival zones, frequently above 3500 m and reaching well over 4500 m. The illustrated plant from Tsochenchen in Bhutan at 3700 m, flowering in June, is typical of these exposed, well-drained high-altitude sites; the caption notes the co-occurring Calathodes palmata.

It is a low, tufted perennial herb arising from a stout, branched, woody rootstock (caudex) clothed in old leaf-bases, forming compact mats. The leaves are digitate (palmate), with several narrow, deeply toothed leaflets that are densely white-tomentose, especially beneath, giving the foliage a silvery, felted appearance adapted to drought and cold. The flowers are borne in lax cymes on slender stems; each has five yellow obcordate petals, an epicalyx alternating with the five calyx lobes, and numerous stamens. The fruit is an aggregate of dry achenes seated on a hairy receptacle.

Within the large and taxonomically complex genus Potentilla, P. saundersiana belongs to a group of densely tomentose, alpine cushion cinquefoils, and infraspecific variants such as var. jaquemontii reflect variation in indumentum and leaflet form across its wide range. Abundant and widespread, it is of no conservation concern.

Author: Franch. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Potentilla (Th. Wolf monograph)

Rosaceae

Potentilla sundaica

by GP Jürgens

(Blume) W.Theob.

Bh09 186 G323
Bhutan Phajoding, 3700m June

Description

Potentilla sundaica (Blume) W.Theob. is a widespread perennial cinquefoil ranging across tropical and subtropical Asia from the Himalaya (Nepal, Bhutan, northern India, Pakistan, Afghanistan) through China, Korea, Japan and Taiwan into South-East Asia, Indonesia, Sri Lanka and the Russian Far East, the GBIF dataset recording some 5,300 occurrences over this broad area. It is a plant of open grassy slopes, forest clearings, roadsides, streambanks and disturbed montane ground, ascending from lowland to high-montane elevations. The illustrated collection comes from Phajoding above Thimphu in Bhutan at 3700 m in June, near the upper part of its altitudinal range, where it grows in moist alpine to subalpine turf.

It is a slender perennial or sometimes short-lived herb with ascending to decumbent, often reddish, hairy stems arising from a slender rootstock. The leaves are mostly ternate, occasionally with an additional pair of leaflets, the leaflets obovate to oblong-cuneate, coarsely serrate to dentate in the upper part and clothed with appressed to spreading hairs; the leaves are stipulate at the base. The flowers are borne in lax, few- to several-flowered cymes, each with an epicalyx of bracteoles alternating with the five calyx lobes and five obovate yellow petals roughly equalling or shorter than the sepals. Numerous stamens surround a domed receptacle bearing many carpels. The fruit is an aggregate of small, smooth to faintly wrinkled achenes seated on a slightly hairy receptacle.

Long known under the name Potentilla kleiniana, this species is a member of the taxonomically difficult P. sundaica complex, whose variable leaf division and indumentum have generated numerous synonyms and infraspecific names across its vast range. As a hardy colonist of open and disturbed habitats it is ecologically a pioneer of grasslands and trodden ground, and it is a frequent component of grazed montane pasture. Given its abundance and ecological amplitude it is of no conservation concern, ranking among the more ubiquitous Asian cinquefoils.

Author: (Blume) W.Theob. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Potentilla of the Sino-Himalaya (Soják)

Primulaceae

Primula buryana

by G & P Jürgens

Balf. f.

Nepal 99 540 ergebnis
West-Nepal Churta-Khola 4100m, June

Description

Primula buryana is a high-alpine primrose of the central and western Himalaya, recorded from Nepal and adjacent south-central China (Xizang), with around one hundred and twenty-two GBIF occurrences indicating a localised but well-documented range. It grows in damp alpine meadows, on grassy and rocky slopes, beside snowmelt rills and in moist turf above the treeline, typically around 4000 to 4500 m. The illustrated plant from the Churta-Khola in West Nepal at 4100 m, flowering in June, is characteristic of its early-summer phenology, blooming shortly after the snow retreats from the high pastures it favours.

The species is a small perennial herb forming a basal rosette of leaves that are often farinose (mealy with white or yellowish farina) and oblong to spathulate with crenate to denticulate margins. From the rosette rises a slender scape bearing a one- to several-flowered umbel subtended by an involucre of bracts. The flowers are heterostylous (pin and thrum), with a tubular calyx and a salverform to funnelform corolla that is violet to purple or pinkish with a contrasting yellowish or white eye. The fruit is a small capsule shorter than or about equalling the calyx, releasing numerous angular seeds.

Primula buryana is an accepted species placed within the petiolarid alliance of Primula (Primulaceae), the Himalayan group of farinose, small-statured alpine primroses. Its heterostyly promotes outcrossing, while the farina and compact rosette habit are adaptations to high insolation and the brief, moisture-rich alpine season. The species has a restricted range and, although not formally assessed, its dependence on intact high-altitude wet meadows makes it potentially vulnerable to grazing and climatic change.

Author: Balf. f. · Sources: POWO (Kew), GBIF, Annotated Checklist of the Flowering Plants of Nepal, Flora of China, Richards monograph Primula (Primulaceae)

Primulaceae

Primula calderiana

by GP Jürgens

Balf. f. & R.E. Cooper

Sikkim2011 266
Sikkim Lada-La 4000m, June
Sikkim2011 335
Sikkim Lada-La 4000m, June
Bh09 120 P192
Bhutan Jimilangtso, 4000m June
Bh09 150 G268
Bhutan Jimilangtso, 4000m June
Sikkim2004 211 G358
Sikkim/India Gometang 4200m May

Description

Primula calderiana is an eastern Himalayan alpine primrose distributed through Nepal, India (Sikkim), Bhutan and adjacent China, with about 313 georeferenced records; isolated entries from Japan and elsewhere reflect cultivation or data artefacts. It grows on moist alpine meadows, damp turf, streamsides and the margins of melting snow between roughly 3500 and 4500 m. The documented localities at Lada-La (4000 m) and Gometang (4200 m) in Sikkim and at Jimilangtso (4000 m) in Bhutan, flowering in May and June, capture its appearance just after snowmelt in the high pastures.

It is a stout, scapose perennial with a basal rosette of obovate to spathulate leaves that are toothed at the margin and often dusted beneath with whitish or yellowish farina. The leafless scape bears a terminal umbel of several flowers, each subtended by linear bracts. The corolla is salver- or funnel-shaped with a slender tube and spreading limb of five notched lobes, ranging from deep purple to crimson with a contrasting yellow or dark eye, and a campanulate calyx. The fruit is a small capsule containing numerous seeds.

Primula calderiana belongs to section Petiolares, a notoriously difficult group whose species hybridise and intergrade across the eastern Himalaya; it is closely allied to P. tsariensis and related farinose primroses. As an early-flowering snowmelt specialist it is an indicator of intact alpine turf, and like many high-elevation Petiolares it is locally collected for gardens. It remains widespread within its core range.

Author: Balf. f. & R.E. Cooper · Sources: POWO (Kew), GBIF, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Richards' Primula monograph

Primulaceae

Primula caveana

by GP Jürgens

W.W. Smith

BhutanPG2011 557 01 1
Bhutan Ludlow-Sherriff-Trail Dem-Tso, 4600m July
BhutanPG2011 558 1
Bhutan Ludlow-Sherriff-Trail Dem-Tso, 4600m July

Description

Primula caveana is a diminutive high-alpine primrose of the eastern Himalaya, recorded from Nepal, India, Bhutan and adjacent China, with about 115 georeferenced occurrences indicating a restricted range at extreme elevation. It is a plant of cold, exposed screes, rock crevices, moraine and damp gravelly turf near the upper limit of vegetation, generally between roughly 4200 and 5000 m. The documented gathering from Dem-Tso on the Ludlow-Sherriff Trail in Bhutan at 4600 m, flowering in July, is fully characteristic of its harsh, late-season nival habitat where snow persists late and the growing season is brief.

It is a small, farinose, scapose perennial forming a tight basal rosette of obovate to spathulate leaves that are toothed toward the apex and densely coated, especially beneath, with conspicuous yellowish or white farina. The short scape bears a few-flowered umbel subtended by farinose bracts. The corolla is salver-shaped with a slender tube and a spreading limb of five notched lobes, deep blue to violet with a yellow or white meal-dusted eye, set in a powdery campanulate calyx. The fruit is a small capsule with numerous seeds.

Primula caveana belongs to section Soldanelloides (allied to the Petiolares group), a cluster of high-elevation, farinose primroses that are taxonomically intricate and often hybridise. The heavy farina is interpreted as protection against intense ultraviolet radiation and water loss at extreme altitude. As a narrowly distributed nival specialist confined to the highest meadows and screes, it is of particular interest for monitoring the effects of alpine climatic change.

Author: W.W. Smith · Sources: POWO (Kew), GBIF, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Richards' Primula monograph

Primulaceae

Primula concinna

by GP Jürgens

G.Watt

BhutanPG2011 562 01
Bhutan Ludlow-Sherriff-Trail Dem-Tso, 4600m July
Nepal 97 183 P363
Nepal Tayla-La 4500m April

Description

Primula concinna is a dwarf high-alpine primrose of the eastern Himalaya, recorded from Nepal, India, Bhutan and south-west China (with a cultivated record in Japan) across 123 georeferenced occurrences. It is a plant of the upper alpine zone, growing in short turf, on moist gravelly slopes, rock ledges and the margins of snow-melt flushes. The collections at Dem-Tso on the Ludlow-Sherriff Trail in Bhutan (4600 m, July) and Tayla-La in Nepal (4500 m, April) place it among the highest-altitude primulas, typically between about 4000 and 5000 m, flowering as the snow recedes.

It is a diminutive rosette-forming perennial herb, often only a few centimetres tall. The leaves are spathulate to oblanceolate, crowded into a flat basal rosette, with toothed or crenate margins and frequently a coating of pale farina (mealy powder) beneath. The flowers are borne singly or in a small umbel on a short scape, each with a tubular calyx and a rose-purple to lilac-pink corolla with a yellow or whitish eye, the limb flat and the lobes notched. The species is heterostylous (pin and thrum forms), and the fruit is a small capsule shorter than or about equalling the calyx.

Primula concinna belongs to the predominantly Sino-Himalayan section Minutissimae, a group of tiny, high-altitude, often farinose primulas distinguished by their cushion or rosette habit and solitary to few-flowered scapes. The heterostylous flowers promote outcrossing by alpine insects, chiefly bees and flies. Restricted to high, often remote terrain and locally frequent there, it faces few direct threats, though as a high-mountain specialist it is potentially sensitive to climate-driven shifts in snow cover.

Author: G.Watt · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Flora of Nepal, Richards Primula (monograph)

Primulaceae

Primula dickieana

by GP Jürgens

G.Watt

Sikkim2011 40
Sikkim Vista-valley 3700m, June
Sikkim2011 41
Sikkim Vista-valley 3700m, June
Sikkim2004 388 P666
Sikkim Lachung 3100m, May
Sikkim 2006 357 ergebnis
India West-Bengal Tamrong 2750m, May

Description

Primula dickieana is an eastern Himalayan primrose ranging through China, Nepal, India, Myanmar and Bhutan, with about 202 GBIF records concentrated in the Sikkim–Bhutan sector. It is a plant of moist alpine meadows, damp turf and seepage slopes, typically between roughly 2700 and 4500 m. The cited collections span this gradient, from Sikkim's Vista valley at 3700 m and Lachung at 3100 m to Tamrong in West Bengal at 2750 m, flowering in May and June as snowmelt saturates the high pastures. It thrives where cool, humus-rich soils remain reliably wet through the early growing season.

The species is a small, tufted, perennial herb forming a basal rosette of leaves that are oblanceolate to spathulate, narrowed to a winged petiole, with crenate to entire margins and an efarinose (mealless) surface. A single slender scape bears a solitary terminal flower, or occasionally a few, the corolla rotate and showy in proportion to the plant. Flower colour is notably variable, ranging from yellow through cream, pink and purple to nearly white, with a tubular calyx and a corolla limb of broad, often emarginate lobes. The fruit is a small capsule enclosed within the persistent calyx, dehiscing to release numerous minute seeds.

Within Primula, the species is placed in section Yunnanensis (formerly allied to section Dickieana), a group of single-flowered alpine primulas, and its remarkable colour polymorphism has long interested monographers. Pollination is effected by alpine insects visiting the open corolla. The species is locally common within its narrow alpine band but, like many Sino-Himalayan primulas, is potentially vulnerable to upslope habitat compression under a warming climate and to trampling and grazing in accessible high pastures.

Author: G.Watt · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China (Primulaceae), Richards Primula (monograph)