10-1 1 mm long, 4 mm wide. Lateral sepals spreading, 12-14 mm long, 9-10 mm wide, with a broad 2 mm wide, ancipitous keel on the mid-vein of the outer surface. Mentum 8 mm long, broadly conical. Petals incurved, elliptic, oblanceolate, acute, 1 1 mm long, 4 mm wide. Lip 3-lobed, recurved in apical third, 10 mm long, 8 mm wide, glandular-pubescent within; side- lobes narrowly oblong, erect; mid-lobe oblong-ovate, acute; callus a low fleshy ridge in the basal half of the lip. Column broad, fleshy, 3.5 mm long; foot 7-8mm long, white, faintly purple-flecked and with a pale yellow apex.

DISTRIBUTION. Central Tanzania only; altitude 1,300-1,600 m.

Polystachya melliodora Cribb in Die Orchidee 34(5): 192 ( 1 983) and in F1. Trop. E. Afr., Orchidaceae 2: 405 (1984). Type: Tanzania, Mufindi, Luhota Forest, cult. Kew, Cribb, Grey-Wilson & Mwasumbi 11445 (holotype K!).

CONSERVATION IN NEPAL I, THE LANGTANG NATIONAL PARK

Tony Schilling

The Langtang National Park, which was gazetted in 1976, lies approximately 50 km to the north of Kathmandu and close to the international border with Xizang (Chinese Tibet). It was established for six urgent and important reasons, namely: 1, to conserve and protect the special types of flora and fauna within its boundaries; 2, to slow and contain erosion and protect the hydro-electric schemes which are fed by its waters; 3, to assist local economy by the encouragement of well-controlled wilderness-orientated tourism; 4, to maintain the Gosainkund area as an important historically religious site; 5, to conserve different ecological communities including those which have been modified and altered by long- established and traditional agricultural usage; 6, to help and maintain the traditional Thamang and Sherpa ethnic cultures.

The Park comprises 1,7 10 sq km and lies at an average altitude of 4,000 m. It covers an incredibly varied topography including the upper Trisuli Valley as far north as Rasua Garhi, the main Langtang Valley, the entire length of the Gosainkund mountains and their holy lakes, plus the northern section of the Helmu district which lies to the south of the high pass of the Ganga La. It is the largest of Nepal’s four National Parks (the others being The Royal Chitwan, Lake Rara and Everest or, more correctly and to give it its Nepalese name, Sagarmatha) and as such fulfils a conservation need for very

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Map o i central Nepal showing the position of the Langtang National Park, 1,7 I0 sq km in extent.

widely differing habitats, ranging from low warm-temperature forests to the high-altitude extremes of biological existence and beyond.

The Langtang Valley is often referred to as one of the loveliest valleys in all Nepal, being narrow and deep with dense mysterious forests of conifers, rhododendron, maple, oak and birch, as well as countless soaring peaks. It is generally known as ‘The Valley of Glaciers’, its upper limits being blocked off by a vast complex of glaciers fanning down from the maze of white castellated peaks which comprise Jugal Himal to the east, the Ganga La range to the south and the ice-fluted complex ridges of the Langtang Himal to the north; the latter reaches its meridian at the 7,220m summit of Langtang Lirung. Lying as it does to the north of the protective Gosainkund and Ganga La mountains, the flora of the east-west running Langtang Valley is significantly affected by a pronounced rain-shadow pattern and, because of this climatic phenomenon, it possesses a particularly interesting and specialized vegetation character which is typical of the drier inner valleys of the Nepalese Himalaya.

In sharp contrast, the wetter southern flanks of the Gosainkund

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mountains and the upper reaches of the Helmu district are fully exposed to monsoon influences, and exhibit no such diminished precipitation pattern. In consequence these variations in climate produce very noticeable ecological differences within the Park’s boundaries.

In the warm-temperate lower regions of the Trisuli Valley, orchids abound on rocks and the dominant trees are Schima wallichii and Pinus roxburghii. As the trail ascends, the July traveller can enjoy the sight of Cornus capitata (Benthamidia capitata) , its cream-coloured bracts wafting in the heavy monsoon air, and pass along hillsides which hold many other interesting plants of this zone including Colquhounia coccinea, Hypericum uralum and Rhus succedanea.

At the Thamang village of Dunche, the Trisuli Khola Valley turns east leading up towards the historic and holy lakes ofGosainkund. In August these lakes draw hundreds of Hindu pilgrims to their shores. In the early part of the nineteenth century, Nathaniel Wallich, who was resident in Nepal but strictly limited in his freedom of travel, took advantage of this religious movement and obtained many of his collections by proxy from the otherwise forbidden mountains of the Gosainkund. These included the type collections of Betula utilis and Gentiana ornata as well as numerous other fine plants.

The majority of visitors to the Park continue directly northwards from Dunche and then turn sharply eastwards into the lower gorge of the great Langtang Valley. Here the hot south-facing wall, which constitutes the northern side of the valley, is ideal for warm

Gentzana ornata

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temperate xerophytic flora. Euphorbia royleana and Kalanchoe spathulata are a common sight as also are langur monkeys that practise amusing and hair-raising Himalayan acrobatics across the vegetated cliffs which plunge directly into the pounding river. The opposite north-facing side of the valley is cooler and lusher and the mixed forest is rich and varied. Laurels are especially abundant and include massive trees of Persea duthiei with Neolitsea pallens and Cinnamomum tamala as an understorey. The strange and atypical labiate, Leuco- sceptrum canum, is also a frequent sight and massive trees of Acer sterculiaceum, A l m s nepalensis and Betula alnoides (the latter over 28 m tall) entice one on to the dense, cool-temperate forest which holds court in the middle section of the valley. In the spring these immensely deep forests of Abies spectabilis, Tsuga dumosa and Quercus semecarpajolia are alive with the song of birds and Rhododendron arboreum, R. barbaturn and P+tanthus nepalensis add spectacular colour to the otherwise sombre forest scene.

During the monsoon, however, there is colour presented by the pink of Androsace sarmentosa var. watkinsii on mossy banks, the purple of Roscoea procera in the more open glades, and the strange yellow- brown flowers of the terrestrial orchid Calanthe tricarinata in the deeper shade. Vicious chest-high stinging nettles (Gerardinia diversi- fo l ia) grow amongst the rocks and command caution and respect. This part of the valley is exceptionally narrow, deep and awe- inspiring. T o the north, above the dense canopy of trees, the dizzy cliffs soar high into the sky towards the 6,565 m westernmost peak of the Langtang massif. Across the deafening roaring water of the Langtang Khola, an almost unbroken mass of coniferous forest covers the lower slopes of the precipitous mountain-sides which form the 4,560 m high southern wall of the valley. Higher, where the trees give out, forbidding crags fade into the frequent mists; here is the Nepal Himalaya at its most beautiful and magnificent.

Farther up the valley beyond Ghora Tabela the heavy forest thins, and becomes less continuous. Glades occur in the now wider valley floor, littered with moss-covered rocks and carpeted in a chaos of dwarf Berberis species, the purple form of Rhododendron lepidotum, and Rosa sericea.

As the forest depths are left behind, and the Sherpa village of Langtang at 3,270m draws close, the now open valley boasts scattered shrubs of Cotoneaster microphyllus, Philadelphus tomentosus, Deutzia hookeriana and Spiraea bella. In summer the yellow Himalayan

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poppies, Meconopsis gracilipes and M . paniculata, show amongst the damp rocks as well as in the lee of the shade-giving shrubs such as Rosa macrophylla; in early spring Euphorbia wallichii creates splashes of gold beside the trail.

In the vicinity of the village, on ancient morainic slopes as well as elsewhere in the upper valley, one of the Park’s most interesting coniferous species occurs, namely Larix himalaica. The Himalayan larches (L. grzfithiana, L. himalaica and L. potaninii) range through south-west China, Xizang, Bhutan, Sikkim and Nepal and these closely related and confusing species are of great interest to phyto- geographers and taxonomists alike. Until very recently the Langtang larch was considered to be a form of I,. potaninii, but research has shown that it is quite distinct. Larix himalaica has a very limited distribution in central Nepal and also occurs disjunctly across the border in Xizang, its locus classicus being on the norther flanks of Everest at an altitude of 3,500 m. It was introduced to Britain from Nepal by Adam Stainton in 1971 but, like its close Himalayan relatives, it is not proving easy to cultivate.

Rhododendron cnuianianum

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Another very rare plant of this region of Nepal is the mauvish pink-flowered Rhododendron cowanianum which occurs erratically at approximately 3,500 m. This deciduous shrub is truly endemic to central Nepal and occurs only in the Langtang National Park and those areas immediately to the west as far as Annapurna. It is loosely allied to R. lefiidotum and was first discovered in a lateral valley of the Langtang by the late Oleg Polunin in June 1949 (Polunin 175). Five years later it was found again by Stainton, Sykes and Williams ( S S & W 9097) in the vicinity of the Annapurna mountains and introduced to cultivation as seed. In the Langtang National Park it grows at the edges of BetulalRhododendron forest on scree-slopes or in clearings, as well as amongst rocks in river beds, but nowhere is it abundant. T o date, R. cowanianum has not proved easy to grow in gardens and remains extremely rare even in specialist collections.

In the steep north-facing forests, Abies, Juniperus and evergreen Rhododendron species add contrast to the otherwise dominant swathe of Betula, Acer, Sorbus and Larix. Amongst this woody tangle of sub- alpine vegetation occurs yet another rare and endemic Nepalese tree which has been tentatively identified as Prunus himalaica. This Prunus, which is closely related to P. rufa, is in the section Magnicupula and was first discovered by Kitamura west of the Langtang region. Its chief horticultural merit lies in the beauty of its bark which is comparable to the well-known Prunus serrula but differs in being a darker mahogany colour; it is also faster growing and the leaves are markedly pubescent. I collected material in 1965 from an altitude of 3,950 m and plants which have been subsequently propagated from this original introduction (Schilling 1138) are now established in several British arboreta.

Still higher up the valley, close to the settlement of Kyangjin Ghyang and beyond the ancient vegetated moraines, the valley scene finally becomes truly alpine. Drifts of Iris kamaonensis are abundant and tussocks of Potentilla Jruticosa var. rigida ( P . arbuscula) litter the stony flats close to the yak pastures. Higher up the mountain-sides impressive drifts of Rhododendron setosum create a rose-purple haze in July, and the small white-belled Cassiope fastigiata grows in such abundance that at a glance it can almost be mistaken for a light covering of snow. The sweet-scented Primula involucrata hugs the wet rocky stream-sides and Pedicularis species (P. oederi and P. siphonantha) grow in association with the delicate Lloydia serotina on grassy ledges. Higher still, on the edge of grim moraines around the valley’s head,

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Iris kamaonensi.r

the strange and woolly Saussurea gosgpiphora may be found. This is but one of several interesting Himalayan alpine plants which exhibit extreme adaptions to the desiccating conditions which exist at extreme altitudes.

In late summer and early autumn the 5,200 m high Ganga La pass can usually be negotiated southwards in order to gain access to the upper valley of the Helmu district which forms the south-eastern section of the Park. Alternatively, by returning back down the Langtang Valley, a different way can be taken, via the villages of Syabru and Sing Gompa, up to the holy lakes of Gosainkund and thence over the 4,720m Lauribini pass; this in turn leads one southwards to the Kathmandu Valley.

On the way, if the month is April and the eye is keen, perhaps that gem of petiolarid primroses, Primula aureata, with lovely heavily farinose gold flowers will show itself to the traveller. This is yet another plant which is endemic to a very limited area of central Nepal. I t first blossomed in cultivation in 1939 at Edinburgh Botanic Garden following an accidental introduction via the Lloyd Botanic

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Primula aureata

Garden, Darjeeling, from seed (labelled Swertia purpurea!) supposedly collected in Sikkim. It was not until 1952 that it was eventually found growing wild in central Nepal by Mrs D. Proud who sent a dried specimen to the British Museum (Natural History) herbarium. Most, if not all, other petiolarid primulas are native to mossy ledges or damp ground in Sino-Himalayan forests, but the rare P. aureata is exceptional in being restricted to damp rock crevices on steep or overhanging cliffs a t altitudes ranging from 3,600-4,300 m.

The Langtang National Park is still young and is only just entering its second decade since formal establishment. Problems of mis- management and over-grazing still require sophistication, but the general message the visitor receives is a hopeful one.

I first trod the wild Langtang Valley in the monsoon of 1965 as a privileged member of a Nepalese government botanical expedition, and at a time when the area was still restricted and far beyond the busy world of trekker-tourism; I returned in the spring of 1986 wondering what might have occurred to its fragile ecosystems, but was pleasantly surprised by the overall measures of control which have been achieved.

There is an official check-post on the road to Dunche and a very well-manned National Park check-post and headquarters halfway up the main Langtang Valley at Ghora Tabela. This is adequately

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staffed by armed Nepalese army personnel. In addition, there is also a well-built hostel-style Park Lodge at Kyangjin which affords simple accommodation to individual trekkers, that is, those who are independent of trekking company support. The cutting of firewood by residents of the Park is officially monitored and controlled, and all foreign visitors and large trekking parties are obliged to cook on kerosene or pressurized gas stoves. Some abuse of these regulations is evident at times, but in the main they are working fairly well.

The Langtang National Park is unique in many ways. Within its boundaries the eye may perceive much of great natural beauty and interest; the sky-blue autumn-flowering Gentiana ornata, the diminutive endemic Poa langtangensis, the clean white chiselled peaks at the head of ‘The Valley of Glaciers’, the powerful thundering waters of the river which they feed, or the dense dark forests which dominate its heart. It is gratifying to know that it is now a protected beauty. It is also gratifying to realise that, given good and continued management, it will be spared and conserved by our generation for other to nurture in their turn.

RUBUS PROCERUS ‘Himalayan Giant’

Douglas H. Kent

Few blackberries found wild in the Northern Hemisphere produce fruit of the quality required to justify their cultivation, but the one most frequently grown in Britain is probably Rubus prucerus P.J. Mueller ‘Himalayan Giant’, sometimes called the American Black- berry. This is a large robust plant with high-arching, often purplish stems sometimes over 6 m long, bearing strong, broad-based prickles, and leaflets white-felted below, with exceptionally large terminal ones, and pink (rarely white) flowers sometimes more than 3 cm in diameter; it is a prolific cropper bearing numerous clusters of large juicy black fruits, which in 1914 the Royal Horticultural Society’s Fruit Committee considered ‘of excellent flavour but rather more acid than our native blackberry’ (J . Roy. Hort. SUC. 40: clxxiv, 19 15). E.A. Bunyard (1918), a nurseryman and fruit grower of Maidstone, on the other hand, described the fruits as ‘lacking flavour’, and Watson (1958) omitted the plant from his list of best-flavoured blackberries.

The diagnostic characters of R. procerus separate i t from R. laciniatus

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