Author

GP Jürgens

Rosaceae

Prunus rufa

by GP Jürgens

Wall. ex Hook.f.

Bhutan2014 434
Bhutan Pele-La 3000m, May
Bhutan2014 543
Bhutan Pele-La 3000m, May

Description

Prunus rufa, the Himalayan cherry, is a small tree of the eastern Himalaya, distributed through Nepal, Bhutan, northern India, China (south-eastern Tibet) and Myanmar, with GBIF logging 290 occurrences concentrated along this Sino-Himalayan belt. It grows in cool temperate and sub-alpine forest, on open slopes, forest margins and in mixed conifer-broadleaf woodland, broadly between 2700 and 3700 m. The photographed plant from the Pele-La pass in central Bhutan at about 3000 m, flowering in May, illustrates its spring blossoming as new growth emerges in the high passes, where it is valued for its striking bark and early flowers.

The species is a deciduous tree, often 5-12 m tall, conspicuous for its smooth, glossy, coppery to reddish-brown peeling bark, which gives rise to the epithet rufa. Young shoots and leaf undersides are clothed in distinctive rusty (rufous) hairs. The alternate leaves are ovate to elliptic, serrate at the margin, acuminate and short-petiolate. The flowers are solitary or in small clusters, opening with the young foliage; each is pentamerous with five white to pale pink petals, numerous stamens and a single carpel seated in a cupular hypanthium. The fruit is a small ovoid drupe, ripening reddish, with a thin flesh surrounding a single hard stone (endocarp).

Described by Wallich ex Hooker, the species belongs to genus Prunus subgenus Cerasus (the true cherries), within Rosaceae subfamily Amygdaloideae. Its rusty indumentum and burnished bark are diagnostic and make it a notable ornamental, cultivated in temperate gardens for its bark and spring flower. The drupes provide food for birds and mammals, aiding seed dispersal. With a broad Himalayan range it is not globally threatened, though high-elevation forest fragmentation and logging may locally reduce populations.

Author: Wall. ex Hook.f. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, The Plant Hunter's Guide to Asian Prunus (Cerasus monograph)

Asteraceae

Pseudognaphalium affine 

by GP Jürgens

(D.Don) Anderb.

Nepal 2001 436 ergebnis ergebnis
Nepal (Gorkha) Gunda 1850m, May

Description

Pseudognaphalium affine is a widespread woolly cudweed of East Asia and the Indo-Himalaya, ranging across China, Japan, Korea, Taiwan, the Himalaya (Nepal, India, Bhutan, Pakistan, Afghanistan), Myanmar, Thailand, Sri Lanka and South-East Asia, and now naturalised more widely (with records as far afield as Argentina and Georgia); its very large dataset of over 7400 georeferenced occurrences confirms its abundance and weedy success. It grows on open grassy slopes, field margins, fallow ground, roadsides and other disturbed sites from the lowlands to the mid-montane belt, broadly from near sea level to about 2500 m. The plant recorded near Gunda in Gorkha, Nepal, at 1850 m in May is typical of such open, sunny, anthropogenic habitats.

It is an annual or biennial herb with erect, simple or branched stems clothed, like the foliage, in dense white-woolly (arachnoid) tomentum. The leaves are alternate, oblanceolate to spathulate, sessile and somewhat decurrent, grey-green and persistently woolly on both surfaces. The numerous small, discoid capitula are aggregated into dense terminal corymbs; each head is enclosed by several rows of pale yellow to straw-coloured, scarious involucral bracts, the florets all tubular, the outer female and filiform, the inner bisexual. The fruit is a tiny oblong cypsela bearing a pappus of slender, basally connate bristles aiding wind dispersal.

Formerly placed in Gnaphalium, this species was transferred to Pseudognaphalium on the basis of capitulum and pappus characters within tribe Gnaphalieae. It is used in East Asian cuisine and folk medicine and is a familiar ruderal weed; its broad ecological tolerance and prolific seed make it abundant and entirely unthreatened.

Author: (D.Don) Anderb. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Nepal, Flora of Bhutan, Anderberg's monograph of the Gnaphalieae

Orobanchaceae

Pterygiella tenuisecta 

by GP Jürgens

(Bureau & Franch.) Pinto-Carr., E.Rico & M.M.Mart.Ort.

Bh09 414 P652
Bhutan Paro, 2500m June

Description

Pterygiella tenuisecta (Bureau & Franch.) Pinto-Carr., E.Rico & M.M.Mart.Ort. is a hemiparasitic annual herb of the Sino-Himalayan region, distributed through Bhutan, northern India and south-western China (notably Yunnan and Sichuan), with the GBIF dataset of roughly 883 occurrences also carrying determinations referable to material in Japan. Often treated under the name Phtheirospermum tenuisectum, it occupies open grassy slopes, forest margins, scrub and disturbed banks at montane elevations, where like other root-hemiparasites it attaches to the roots of neighbouring grasses and herbs while retaining functional green foliage. The illustrated plant was photographed at Paro in western Bhutan at around 2500 m in June, an elevation and season typical of its flowering in the temperate montane belt.

It is a slender, erect to ascending annual with branched, glandular-pubescent stems. The leaves are opposite below and may become alternate above, the blades pinnatisect to bipinnatisect with narrow, almost filiform ultimate segments, giving the foliage a finely divided, feathery appearance reflected in the epithet tenuisecta. The flowers are solitary in the upper leaf axils, shortly pedicellate, with a tubular, ribbed, glandular calyx of fused sepals. The corolla is yellow, two-lipped, the upper lip hooded and the lower three-lobed and spreading, enclosing four didynamous stamens. The fruit is a loculicidal, ovoid to oblong capsule containing numerous small seeds.

The species has been shuttled between several genera of the broomrape family, having been described in Gerardia and later placed in Phtheirospermum before molecular and morphological work supported its transfer to Pterygiella; the synonymy underlies the differing names on the source page. As a facultative hemiparasite it plays a part in regulating grassland community structure, drawing water and nutrients from hosts while contributing its own photosynthesis. No conservation concern is recorded, the plant being a widespread component of seasonally moist montane grasslands across its Sino-Himalayan range.

Author: (Bureau & Franch.) Pinto-Carr., E.Rico & M.M.Mart.Ort. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Orobanchaceae phylogenetic studies (Pinto-Carrasco et al.)

Lythraceae

Punica granatum

by GP Jürgens

L.

Bhutan2014 69
Bhutan Kadi 1600m, May

Description

Punica granatum, the pomegranate, is a deciduous shrub or small tree native to the region from Iran and the Transcaucasus through Central Asia, now cultivated and naturalised worldwide; its 51453 GBIF occurrences span Mediterranean Europe, the Middle East, India, China, the Americas, Africa and Australia. It thrives in warm, semi-arid to subtropical climates on a wide range of soils, favouring sunny, well-drained sites, and tolerates drought and seasonal heat. The plant recorded at Kadi in Bhutan at 1600 m in May represents a cultivated or naturalised occurrence in the warm Himalayan valleys, flowering in late spring as temperatures rise.

The species is a much-branched shrub or small tree, often spinescent, with smooth grey bark and frequently angular young shoots. The leaves are opposite or subopposite, simple, entire, oblong to obovate, glossy and glabrous, often coppery when young. The showy flowers are solitary or clustered, with a thick, leathery, persistent campanulate hypanthium bearing 5-8 fleshy lobes and crumpled, bright scarlet to orange-red petals enclosing numerous stamens and an inferior ovary. The fruit is the distinctive balausta, a large, leathery-rinded berry crowned by the persistent calyx and partitioned internally into chambers packed with seeds enveloped in juicy, translucent, edible arils.

Long placed in its own family Punicaceae, Punica is now embedded within Lythraceae on molecular evidence, with the genus comprising only P. granatum and the Socotran P. protopunica. The pomegranate is among the most anciently cultivated fruit crops, valued for its edible arils, ornamental flowers and medicinal uses, and is widely grown across the warmer Himalayan foothills and adjacent plains.

Author: L. · Sources: POWO (Kew), GBIF, Flora of China Vol. 13, Flora of Bhutan Vol. 2, Flora of Nepal, Flora of Pakistan, Graham's revision of Lythraceae

Brassicaceae

Pycnoplinthopsis bhutanica

by GP Jürgens

Jafri 

BhutanPG2011 253
Bhutan Jule-Tso, 4000m June

Description

Pycnoplinthopsis bhutanica is a high-alpine crucifer endemic to the eastern Himalaya, recorded from Bhutan, Nepal and India, and one of the rarer plants in this group with only about 33 GBIF occurrences. It is confined to open alpine habitats — stony turf, screes, moraines and rock crevices — at very high elevations, generally around and above 4000 m. The plant photographed at Jule-Tso in Bhutan at about 4000 m in June represents its characteristic setting in cold, well-drained alpine ground near glacial lakes, flowering in early summer as the snow retreats.

The species is a small, cushion- or rosette-forming perennial herb with a stout, often woody taproot crowned by a dense tuft of leaves. The leaves are entire to slightly toothed, somewhat fleshy and crowded, frequently appressed to the ground. The flowers are borne close to the rosette on very short pedicels, with four white to pale lilac or pinkish petals arranged in the cruciform pattern typical of the family and six tetradynamous stamens. The fruit is a short silicula characteristic of the genus, retaining a persistent style and dehiscing to release the seeds.

Pycnoplinthopsis is a small Himalayan genus closely allied to Pycnoplinthus, both being dwarf, cushion-forming high-alpine Brassicaceae adapted to the harsh conditions of the upper alpine and subnival zone. The compact rosette habit, woody rootstock and reduced inflorescence are adaptations to cold, wind exposure and a brief growing season. As a narrow eastern Himalayan endemic of restricted, fragile high-elevation habitats, it is of biogeographic and conservation interest and potentially vulnerable to climate-driven contraction of the alpine zone, although it has not been formally assessed.

Author: Jafri · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Al-Shehbaz systematics of Brassicaceae

Pyrolaceae

Pyrola asarifolia subsp. asarifolia

by GP Jürgens

n.n.

BhutanPG2011 732 01 01
Bhutan Haa-Valley, 2750m July

Description

Pyrola asarifolia subsp. asarifolia is a small evergreen perennial herb traditionally placed in the family Pyrolaceae, now usually treated within Ericaceae (subfamily Monotropoideae). It is a circumboreal taxon, and its GBIF records span North America, eastern Asia and the Himalaya, including the United States, Canada, Japan, China, India and Bhutan, reflecting a broad cool-temperate to boreal range. It grows in moist, shaded coniferous and mixed forest, on humus-rich, often mossy soils, generally between about 2,500 and 3,500 m in its Himalayan stations. The plant illustrated from the Haa Valley in western Bhutan at 2,750 m in July typifies this shaded, damp montane forest-floor habitat.

The species is a low, rosette-forming herb arising from a slender, creeping rhizome. The leaves are basal, long-petiolate, with rounded to broadly ovate or reniform, somewhat leathery and glossy blades that persist through the winter, the shape recalling that of Asarum and giving the epithet asarifolia. The flowering scape is erect and leafless, bearing a many-flowered raceme of nodding, cup-shaped flowers; these are pink to rose-purple, with five spreading petals, ten anthers opening by pores, and a long, characteristically curved and exserted style, a key generic feature. The fruit is a dry, pendent capsule releasing extremely numerous dust-like seeds.

Like other members of the Pyroloideae the plant is partially mycoheterotrophic, supplementing photosynthesis through mycorrhizal fungi that link it to surrounding trees, an adaptation suited to deeply shaded forest floors. The dust seeds depend on appropriate fungal partners for germination. The transfer of the old Pyrolaceae into Ericaceae reflects molecular evidence of their nesting within that family. Widespread across the Northern Hemisphere, the species is not threatened, though its Himalayan populations occupy the southern margin of a primarily boreal distribution and are of phytogeographic interest.

Author: n.n. · Sources: POWO (Kew), GBIF, Flora of China Vol. 14, Flora of Bhutan Vol. 2, Flora of North America Vol. 8, Haber: Systematics of the Pyroloideae

Rosaceae

Pyrus pashia

by GP Jürgens

Buch.-Ham. ex D.Don

Bhutan2012 1264
Bhutan Trashigang 1720m, October

Description

Pyrus pashia Buch.-Ham. ex D.Don, the wild Himalayan pear, is a widespread tree of the temperate Himalaya and adjacent ranges, distributed from Pakistan and Afghanistan through northern India, Nepal, Bhutan and south-west China into mainland Southeast Asia, with scattered introductions elsewhere. It grows in open broad-leaved forest, on forest margins, hillsides and around cultivation in the warm- to cool-temperate belt, generally between about 1000 and 2500 m. The photographed tree from Trashigang in eastern Bhutan at 1720 m, recorded in October when the fruit is ripening, typifies its occurrence in lower-montane forest and the agricultural landscapes where it is often retained or semi-cultivated.

The plant is a small to medium-sized deciduous tree with a rounded crown, the branches sometimes bearing short, stiff spines. The alternate leaves are ovate to elliptic, with finely toothed margins, an acuminate apex and a slender petiole, often hairy when young and turning colour before leaf-fall. In spring, before or with the new leaves, it bears showy corymbs of white, five-petalled flowers with numerous stamens bearing reddish to purple anthers. The fruit is a small, rounded to subglobose brown pome, dotted with conspicuous pale lenticels and gritty with stone cells, becoming sweet and edible only when bletted (over-ripened).

Within the genus Pyrus (Rosaceae, subfamily Amygdaloideae) P. pashia is a key Asian wild pear, valued as a rootstock for cultivated pears and a source of edible fruit and timber. Its blossom attracts bees and other insects, and the fruit is dispersed by birds, mammals and people. The species is widespread, common and of least concern, and is of interest to plant breeders as a reservoir of genetic diversity and disease resistance.

Author: Buch.-Ham. ex D.Don · Sources: POWO (Kew), GBIF, Flora of China (Rosaceae), Flora of Pakistan, Flora of Bhutan, Pears: Botany, Production and Uses

Fagaceae

Quercus glauca

by GP Jürgens

Thunb.

Bhutan2015 571
Bhutan Mo-Chu 1550m, October
Bhutan2015 572
Bhutan Mo-Chu 1550m, October

Description

Quercus glauca, the ring-cupped or Japanese blue oak, is one of the most widespread evergreen oaks of East and South Asia. GBIF documents nearly 14,910 occurrences spanning Japan, China, Taiwan, Korea, Nepal, India, Bhutan, Myanmar, Laos and Pakistan, with numerous introduced records in Europe and North America. It is a dominant or co-dominant of subtropical and warm-temperate broadleaved evergreen forest, frequently on hill slopes, ravines and along watercourses at low to mid elevations. The photographed tree grew in Bhutan along the Mo-Chu at 1550 m in October, a typical mid-montane riparian situation within the species' Himalayan range.

It is an evergreen tree with smooth greyish bark and alternate, coriaceous, oblong-lanceolate leaves whose upper half is conspicuously serrate while the lower margin is entire; the lamina is glossy dark green above and glaucous, often whitish-waxy and pubescent beneath, giving the species its epithet. Young shoots are silky-villous. As a member of subgenus Cerris, section Cyclobalanopsis, it bears its acorns in a distinctive cupule formed of concentric, ring-like fused bracts rather than separate scales; the ovoid nut ripens in a single season. Flowers are unisexual, the staminate in slender pendent catkins, the pistillate few in short spikes.

GBIF accepts the name. Its placement in section Cyclobalanopsis, sometimes treated as a separate genus, unites the Asian ring-cupped oaks. Quercus glauca is an important timber and afforestation tree, widely planted and naturalised, and ecologically central to evergreen oak forests. It is abundant and assessed as of least conservation concern.

Author: Thunb. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, monograph of Asian Quercus (Cyclobalanopsis)

Fagaceae

Quercus lanata

by GP Jürgens

Sm.

Nepal 97 83 P138
Nepal Tankhu 2100m April
Nepal 97 84 P141
Nepal Tankhu 2100m April

Description

Quercus lanata is an evergreen oak of the Himalaya and adjacent uplands, documented in 317 GBIF occurrences across Nepal, Bhutan, India, Pakistan, China, Myanmar, Thailand and Vietnam. It is a characteristic tree of subtropical to lower temperate broad-leaved forest, occurring on hill slopes and ridges, often in association with other evergreen oaks, rhododendrons and laurels, generally between about 1000 and 2400 m. The tree photographed at Tankhu in Nepal at 2100 m in April occupies the mid-montane oak belt, flowering in spring before or with the flush of new foliage on warm, well-drained slopes.

The species forms a small to medium-sized evergreen tree with a rounded crown and bark that is grey and fissured. The leaves are alternate, simple, coriaceous, ovate-lanceolate to elliptic, with serrate or crenate-dentate margins, the lower surface densely covered in a persistent greyish to tawny wool from which the epithet lanata derives. The flowers are unisexual and monoecious, the staminate borne in slender pendulous catkins and the pistillate few, in short spikes. The fruit is an acorn, ovoid, seated in a shallow, scaly cupule, maturing over one season.

Quercus lanata belongs to subgenus Cerris, section Cyclobalanopsis or the ring-cupped oak alliance recognised in older treatments, and has historically been confused with Q. leucotrichophora and other woolly-leaved Himalayan oaks. It is an important component of mid-elevation watershed forests, providing fuelwood, fodder and leaf litter, and is locally subject to pressure from lopping and forest clearance, though it remains widespread and not globally threatened.

Author: Sm. · Sources: POWO (Kew), GBIF, Flora of China Vol. 4, Flora of Bhutan Vol. 1, Flora of Nepal, Flora of Pakistan, Menitsky's Oaks of Asia

Fagaceae

Quercus semecarpifolia

by GP Jürgens

Sm.

Bhutan2014 857
Bhutan Chele-La 3000m, May
Bhutan2014 1039
Bhutan Chele-La 3000m, May
Nepal 99 374 ergebnis
West-Nepal Linji-Khola 3300m, June

Description

Quercus semecarpifolia, the kharsu oak, is an evergreen oak forming the highest-altitude oak forests of the Himalaya, native across China, Nepal, India, Bhutan, Pakistan and Afghanistan and extending into Myanmar and Thailand. It dominates upper montane and subalpine slopes, often at the treeline, generally between about 2400 and 3800 m, on cool, moist exposures. The trees photographed at Chele-La in Bhutan at 3000 m in May and along the Linji-Khola in West Nepal at 3300 m in June illustrate its role as the uppermost broad-leaved forest belt, frequently mixed with rhododendron, fir and birch near the limit of arborescent growth.

It is a large evergreen tree, gnarled and spreading at high elevations, with thick, fissured bark. The leaves are leathery and elliptic to oblong, dark glossy green above and golden- to rusty-tomentose beneath when young, the margin entire or with a few spiny teeth, especially on younger and coppice growth. It is monoecious, the male flowers in slender pendulous catkins and the female flowers solitary or few. The fruit is a large, hemispherical acorn seated in a shallow cup of appressed scales, maturing over a second season and providing important mast.

Quercus semecarpifolia belongs to subgenus Cerris (section Ilex, the ring-cupped oaks), the predominant oak lineage of the Sino-Himalayan mountains. As a treeline keystone it stabilises soils, supports rich epiphyte and understorey communities and yields hard timber, fuelwood and fodder, which makes it heavily exploited and in places poorly regenerating. Its acorns are dispersed by birds and rodents, and the species is regarded as ecologically critical yet locally threatened by overcutting and grazing across the Himalaya.

Author: Sm. · Sources: POWO (Kew), GBIF, Flora of China, Annotated Checklist of the Flowering Plants of Nepal, Flora of Bhutan, Menitsky's Oaks of Asia