Tag:

Subalpine (2500-3500 m)

Paulowniaceae

Brandisia rosea

by G & P Jürgens

W.W.Sm.

Bhutan2012 413
Bhutan Wangdi 2700m, September

Description

Brandisia rosea is a shrubby, often scandent plant of the eastern Himalaya and adjacent China, recorded by GBIF (about 63 occurrences) from China, India and Bhutan, a small total that reflects its restricted range and rather localised occurrence. It inhabits open forests, thickets, forest margins, scrub and rocky slopes in the warm-temperate montane zone, broadly between 2000 and 3000 m. The plant photographed near Wangdi in Bhutan at about 2700 m in September lies within this band and within the autumn flowering season, when its rosy blooms appear among the post-monsoon vegetation of the eastern Himalayan hillsides, a region where the genus reaches the western edge of its distribution.

It is a woody shrub, sometimes clambering or half-scandent, with young branches and foliage characteristically clothed in a fine stellate or scaly indumentum giving a greyish or rusty cast. The leaves are opposite, simple, ovate to lanceolate, entire or nearly so, and often tomentose beneath. The flowers are showy and borne in the leaf axils or in short clusters; the calyx is campanulate and toothed, and the corolla is conspicuously two-lipped (bilabiate), rose-pink to reddish, with the upper lip arched and the lower spreading and lobed, the form and colour suiting pollination by bees or birds. There are four didynamous stamens. The fruit is a loculicidal capsule containing numerous small seeds.

The genus Brandisia has had an unsettled familial history, long placed in the broadly defined Scrophulariaceae and subsequently reassigned; molecular and morphological studies have aligned it with the small woody clade comprising Paulownia and its relatives, hence its treatment here under Paulowniaceae (it is elsewhere placed in Orobanchaceae by some authors, and its position remains debated). Whatever its precise placement, Brandisia is a distinctive Sino-Himalayan element of montane shrubberies. With its limited range and modest number of records B. rosea has not been formally assessed for conservation, but as a habitat-specific montane shrub it would merit monitoring against forest disturbance in its core eastern Himalayan area.

Author: W.W.Sm. · Sources: POWO (Kew), GBIF, Flora of China Vol. 18, Flora of Bhutan Vol. 2, Flora of Nepal, Hong et al. Scrophulariaceae of China

Primulaceae

Bryocarpum himalaicum

by GP Jürgens

Hook.f. & Thomson

Bhutan2014 497
Bhutan Phobjika 2800m, May
Bhutan2014 499
Bhutan Phobjika 2800m, May

Description

Bryocarpum himalaicum is the sole species of its genus, a primuloid herb endemic to the eastern Himalaya and recorded from Bhutan, India (Sikkim), Nepal and southern China; GBIF documents around 86 occurrences across this narrow range. It grows in moss-rich, humus-laden ground in cool, shaded forest, among rhododendron and bamboo thickets and on damp, mossy banks in the upper temperate and subalpine zones, typically between about 2700 and 3700 m. The illustrated plant from Phobjika in central Bhutan at 2800 m, flowering in May, is characteristic of these humid, sheltered montane habitats.

It is a small, delicate perennial herb arising from a slender rhizome, forming a rosette of long-petioled, ovate to cordate, crenate leaves with a soft texture. The flowers are solitary and nodding on slender scapes, the corolla being narrowly tubular to bell-shaped and clear yellow, with a slender tube expanding into five spreading lobes, evoking a miniature pendent primrose. A distinctive feature giving the genus its name is the elongate, beaked, septicidal capsule that buries or lowers itself among the moss as it matures before releasing the seeds.

Bryocarpum is a monotypic genus traditionally allied to Primula and the cyclamenoid primulas within Primulaceae, distinguished by its solitary yellow flowers and peculiar elongate fruiting capsule. Its restricted high-Himalayan range and dependence on undisturbed mossy forest floor make it a botanically significant relict of conservation interest, vulnerable to habitat disturbance and changing montane moisture regimes.

Author: Hook.f. & Thomson · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Primula (J. Richards monograph)

Scrophulariaceae

Buddleja colvilei

by G & P Jürgens

Hook.f.

BhutanPG2011 53
Bhutan Jakar, 2500m June
BhutanPG2011 552011 Bhutan Buddleia colvilei
Bhutan Jakar, 2500m June

Description

Buddleja colvilei is a large-flowered shrub or small tree of the eastern Himalaya, native to Bhutan, India, Nepal and China, and widely grown in temperate gardens, as its 166 occurrences from Britain, North America, New Zealand and Spain attest. In the wild it occupies open temperate forest margins, clearings, stream banks and shrubberies, typically between about 2400 and 4000 m. The plant recorded at Jakar in Bhutan at 2500 m in June represents its early-summer flowering within the moist temperate zone, where it forms a spreading, often arching woody framework.

The plant has stout branches with peeling bark and is clothed, especially when young, in a pale stellate or floccose indumentum. The leaves are opposite, lanceolate to elliptic, acuminate, with finely toothed margins, dark green above and paler and tomentose beneath. The inflorescence is a pendent terminal panicle of relatively few but exceptionally large flowers; the corolla is tubular with a flared, four-lobed limb, deep rose-red to crimson with a pale or whitish throat, and bears the largest flowers of any Buddleja. The fruit is a small two-valved septicidal capsule releasing numerous tiny seeds.

Buddleja is here placed in Scrophulariaceae following the family circumscription used in the source, though the genus is also treated in a segregate family Buddlejaceae and within an expanded Scrophulariaceae in current systems. B. colvilei is celebrated horticulturally for its outsized, vividly coloured flowers and has received garden awards. In its native range it remains locally frequent in disturbed and edge habitats and is not regarded as threatened.

Author: Hook.f. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, A Revision of the Genus Buddleja (Leeuwenberg), Flowers of the Himalaya (Polunin & Stainton)

Scrophulariaceae

Buddleja macrostachya

by GP Jürgens

Benth.

Bhutan2015 445
  Bhutan Jakar 2900m, October
Bhutan2015 446
  Bhutan Jakar 3100m, October

Description

Buddleja macrostachya is a widespread Sino-Himalayan and Indochinese shrub, recorded from China, India, Vietnam, Myanmar, Thailand, Bhutan, Bangladesh and Nepal, with over 400 documented occurrences spanning the eastern Himalaya into mainland Southeast Asia. It is a plant of open hillsides, forest margins, thickets, roadsides and disturbed slopes in subtropical to temperate zones, generally between about 1000 and 3200 m. The illustrated plants from Jakar in central Bhutan at 2900 and 3100 m, flowering in October, demonstrate its autumn flowering at the upper end of its altitudinal range, where it forms conspicuous shrubs in sunny, often disturbed montane habitats.

It is a large shrub with quadrangular, densely stellate-tomentose young branches. The leaves are opposite, lanceolate to narrowly elliptic, long-acuminate, with a crenate-serrate margin, dark green and rugose above and grey- to fawn-tomentose beneath, the bases joined by an interpetiolar stipular line. The inflorescence is a long, narrow, interrupted spike-like thyrse (reflected in the epithet macrostachya, large-spiked) of many congested cymose clusters. Individual flowers are small, with a four-lobed campanulate corolla that is pale lilac to pink or purplish with an orange throat, and four included stamens. The fruit is a small, septicidal, two-valved capsule releasing numerous minute seeds.

Although listed here under Scrophulariaceae following the broad APG placement of Buddleja, the genus is also frequently treated in its own family Buddlejaceae; B. macrostachya Benth. is the accepted name. The nectar-rich, fragrant inflorescences attract butterflies, moths and other long-tongued insects, while the light, winged seeds are wind-dispersed. As a vigorous coloniser of open and disturbed ground it is common and widespread, and of least conservation concern.

Author: Benth. · Sources: POWO (Kew), GBIF, Flora of China Vol. 15, Flora of Bhutan Vol. 2, Flora of Nepal, Leeuwenberg The Loganiaceae of Africa and Buddleja revisions (monograph)

Orchideaceae

Bulbophyllum griffithii

by GP Jürgens

Rchb.f.

Bhutan2012 444
Bhutan Wangdi 2500m, September
Bhutan2012 1171 Kopie
Bhutan Tashiyangtse 2000m, October

Description

Bulbophyllum griffithii is an epiphytic orchid distributed from the eastern Himalayas (Nepal, northeast India, Bhutan) through southwest China (Yunnan) to Taiwan. The species is named after William Griffith (1810–1845), the pioneering British botanist who collected extensively in Bhutan and northeast India. It occurs in cool, humid montane forests at elevations of 1,500–2,800 m, favouring mossy tree trunks in the cloud forest zone.

The pseudobulbs are ovoid to subglobose, 1.5–3 cm tall, widely spaced on a stout rhizome. Each bears a single, coriaceous, oblong-elliptic leaf 8–15 cm long. The inflorescence is an umbel-like, subglobose cluster of 5–12 flowers, carried on a slender peduncle 10–20 cm tall — a floral arrangement typical of section Cirrhopetalum. The flowers are about 2 cm across, pale yellow to greenish with purple-red stripes and spots. The dorsal sepal is erect, the lateral sepals elongated and twisted, and the lip is small, curved, and dark purple. Flowering occurs from August to October.

Within the complex taxonomy of Bulbophyllum section Cirrhopetalum, B. griffithii is recognised by its umbellate inflorescence with relatively few, medium-sized flowers and its distinctive striped pattern. GBIF records confirm a limited distribution centred on the eastern Himalayas and East Asia.

Author: Rchb.f. · Sources: POWO (Kew), Flora of Bhutan Vol. 3, GBIF, Pearce & Cribb: The Orchids of Bhutan (2002)

Orchideaceae

Bulbophyllum muscicola

by GP Jürgens

Rchb.f.

Bhutan2015 56
Bhutan Wangdi Phodrang 2000m, October
Bhutan2012 341 1
Bhutan Dochu-La 3100m, September

Description

Bulbophyllum muscicola is a diminutive epiphytic orchid with a disjunct distribution from the eastern Himalayas (Nepal, northeast India, Bhutan) through Southeast Asia to New Guinea. The specific epithet 'muscicola' (moss-dweller) aptly describes its preferred microhabitat: the species grows embedded in moss mats on tree trunks and branches in cool, humid montane forests, typically at 1,200–3,100 m elevation.

This is one of the smallest Bulbophyllum species in the Himalayan flora. The pseudobulbs are minute, globose to ovoid, 3–8 mm tall, closely set on a threadlike, creeping rhizome. Each pseudobulb bears a single, fleshy, ovate leaf 1–3 cm long. The inflorescence is a solitary flower or a short, few-flowered raceme on a filiform peduncle 2–5 cm long. Flowers are tiny, 3–5 mm across, translucent yellow to orange, with the lateral sepals connate for most of their length. The lip is minute, fleshy, and mobile. Flowering occurs from September to November.

Due to its small size, B. muscicola is easily overlooked in the field and is probably under-recorded. Its occurrence at the Dochu-La pass in Bhutan at 3,100 m places it among the higher-altitude records for the genus in the eastern Himalayas.

Author: Rchb.f. · Sources: POWO (Kew), Flora of Bhutan Vol. 3, GBIF, Pearce & Cribb: The Orchids of Bhutan (2002)

Fabaceae

Cajanus mollis

by GP Jürgens

(Benth.) Maesen

Bhutan2012 406
Bhutan Wangdi 2700m, September

Description

Cajanus mollis (Benth.) Maesen is a trailing or twining legume distributed through the Himalaya and southern and southeastern Asia; GBIF records (about 161 occurrences) span India, Nepal, Bhutan, southern China, Thailand, Indonesia, the Philippines and Pakistan. It grows in open scrub, grassland, forest margins, hedgerows and disturbed slopes at lower and middle elevations, scrambling over surrounding vegetation. The plant photographed near Wangdi in Bhutan at 2700 m in September, flowering and fruiting late in the warm season, sits at the upper part of its altitudinal range in the warm-temperate hill belt, where open, sunny, well-drained slopes suit its sprawling habit.

It is a perennial herb or subshrub with slender, prostrate to climbing stems clothed in soft spreading hairs. The leaves are pinnately trifoliolate, the leaflets obovate to elliptic and densely softly pubescent, gland-dotted beneath, and subtended by small stipules. The flowers are papilionaceous, borne in short axillary racemes; the corolla is yellow, the standard often reddish- or purplish-veined on the outer face, with the keel enclosing the diadelphous stamens. The calyx is campanulate and hairy. The fruit is a flattened, oblong, pubescent pod constricted between the seeds and bearing oblique depressions on the valves, dehiscing to release several small seeds.

The taxon, formerly placed in the segregate genus Atylosia, was transferred to Cajanus by Van der Maesen, who united Atylosia with Cajanus on morphological grounds; it is one of the wild relatives of the cultivated pigeonpea, Cajanus cajan, and is therefore of interest as a genetic resource for crop improvement and disease resistance. As a nitrogen-fixing legume it enriches soil on disturbed ground. Widespread and adaptable, it is of least conservation concern across its broad Asian range.

Author: (Benth.) Maesen · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Van der Maesen revision of Cajanus, Annotated Checklist of the Flowering Plants of Nepal

Orchideaceae

Calanthe chloroleuca

by GP Jürgens

Lindl.

Nepal 97 299 P600
Nepal new Clepua 2370m May
Nepal 97 301 G602
Nepal new Clepua 2370m May
Nepal 2001 147 ergebnis ergebnis
East-Nepal Bhalukhop 2520m, April

Description

Calanthe chloroleuca is a terrestrial orchid of restricted distribution in the eastern Himalayas, known from Nepal, northeast India (Sikkim), Bhutan, and southwest China (Yunnan). With fewer than 20 documented occurrences in GBIF, it is one of the rarer Calanthe species in the region. The species grows in moist, shaded forest understory, on humus-rich soils among leaf litter, at elevations of 2,000–3,000 m.

The plant is an evergreen species with reduced pseudobulbs hidden by leaf bases. It produces 3–5 elliptic, plicate leaves 15–25 cm long. The inflorescence is an erect raceme 20–40 cm tall, carrying 8–15 flowers. The name 'chloroleuca' derives from Greek chloros (green) and leukos (white), accurately describing the flower coloration: sepals and petals are greenish-white, and the lip is white with a greenish or yellowish tinge, trilobed, with low, parallel keels on the disc. The spur is slender, 1–1.5 cm long, slightly curved. Flowering occurs from April to May.

Calanthe chloroleuca is easily confused with the similarly coloured C. brevicornu, from which it differs in its longer spur, narrower lip lobes, and more elongated floral bracts. Its rarity in herbarium collections may partly reflect the difficulty of distinguishing it from congeners in the field.

Author: Lindl. · Sources: POWO (Kew), Flora of Nepal Checklist, GBIF, Flora of Bhutan Vol. 3

Orchideaceae

Calanthe griffithii

by GP Jürgens

Paxton & Lindl.

Bh2008 443 G693
Bhutan Gogona, 3400m April
Bh2008 513 P788
Bhutan Gogona, 3400m April

Description

Calanthe griffithii is a terrestrial orchid of the eastern Himalayas, named in honour of William Griffith, whose botanical collections from Bhutan and Assam in the 1830s–40s remain foundational for Himalayan botany. The species is distributed from Pakistan through Nepal, northeast India, and Bhutan to southwest China. It inhabits cool, moist montane forests and Rhododendron scrub at 1,600–3,500 m elevation, typically growing in deep humus under dense canopy shade.

This is an evergreen Calanthe with short, inconspicuous pseudobulbs. The leaves are 3–5, broadly elliptic, 15–30 cm long, plicate, and persist through winter. The inflorescence is an erect, pubescent raceme 15–30 cm tall, emerging before or with the new leaves. The flowers are 2–3 cm across, typically pale yellow to greenish-yellow, sometimes with a pinkish tinge. The lip is trilobed, the mid-lobe bifid, with raised yellow lamellae on the disc. The spur is slender, 1–1.5 cm long. Flowering in Bhutan occurs from March to May.

The collection locality at Gogona (3,400 m) in Bhutan represents the high-altitude forests of the inner valleys where C. griffithii flowers early in the spring before canopy closure. The species' relatively wide altitudinal range (1,600–3,500 m) reflects its adaptability to various forest types from warm temperate to subalpine.

Author: Paxton & Lindl. · Sources: POWO (Kew), Flora of Bhutan Vol. 3, GBIF, Pearce & Cribb: The Orchids of Bhutan (2002)

Orchideaceae

Calanthe sylvatica

by GP Jürgens

Lindl.

Bhutan2012 448
Bhutan Wangdi 2500m, September

Description

Calanthe sylvatica is a terrestrial orchid with one of the widest distributions in the genus, spanning from tropical and subtropical Africa (East Africa, Madagascar, Réunion, Comoros) to South and Southeast Asia (India, Bhutan, Nepal, Myanmar, China, Thailand, Vietnam). This pantropical range is reflected in GBIF's over 2,700 documented occurrences. In the Himalayas, it grows in the understory of humid broadleaved forests at 500–2,800 m elevation.

The plant is an evergreen species with inconspicuous pseudobulbs concealed by leaf sheaths. Leaves are 3–5, elliptic-lanceolate, 20–40 cm long, plicate, dark green. The inflorescence is an erect raceme 30–60 cm tall, bearing 10–30 flowers. Flowers are 2.5–3.5 cm across, typically deep violet to lilac-purple, though colour varies across the vast range from white to pink to deep purple. The lip is trilobed with a violet mid-lobe and a yellow callus with raised lamellae. The spur is slender, 1.5–2.5 cm long. In the Himalayas, flowering occurs from August to October.

The remarkable biogeographical range of Calanthe sylvatica — bridging Africa and Asia — has made it a subject of interest in orchid phylogeography. The Himalayan populations belong to the Asian lineage, and some taxonomists treat them as a distinct variety or subspecies. The species is adaptable and locally common in suitable habitats.

Author: Lindl. · Sources: POWO (Kew), Flora of Bhutan Vol. 3, GBIF, Cribb & Hermans: Field Guide to the Orchids of Madagascar (2009)