BOTANICAL EXPLORATION IN THE MISHMI HILLS

F. KINGDON WARD.

PROBABLY every generation has boasted to its successors that it has left them no more worlds to conquer. And yet there never were more explorers than there are to-day. The truth is that the geographical outlook, like everything else, has changed with the times. No more worlds to conquer ! Rather are there new worlds for old, and explorers need never despair that the romance of their calling is dead. The paradox of exploration is that as the[field narrows, the objects in the field expand to infinity. If, then, the pioneer has had his day, for the specialist it is only the breaking of the dawn.

The Mishmi Hills are not new ground to the pioneer explorer, nor to the Survey of India, who mapped most of the unadministered trans-frontier territory on the quarter-inch scale in 1911-13⁵ But to the botanist they are virgin soil. Except for Griffith who nearly a century ago visited Sadiya and travelled thence a short distance up the Lohit valley to the foot of the hills, no botanist has ever been into the country. One could safely say of course that the lower hills would be covered with sub-tropical evergreen rain-forest which would bear a general resemblance to the forests of the sub-Himalayan tract from Sikkim eastwards, or to that of the Khasia and Naga Hills south of the Brahmaputra. But apart from the type of vegetation, what of the species composing it ? One might even predict the types of vegetation likely to be met with above 7,000 feet—-as temperate rainforest, rhododendron forest, conifer forest, and, ascending above the tree-line, scrub and Alpine meadow. But it would be quite impossible to forecast what species would be found above 7,000 feet, or even to say what are the affinities of the flora, whether predominantly Himalayan or Burmese, or Chinese, or even Tibetan.

Thus the quest has a twofold interest,—the obvious one of discovering new species, and the more exotic one of finding old plants in new places, with a view to working out distribution, the affinities of the flora, and the probable lines of migration.

Nor is this the end, but rather a means to an end. It was not chance which took us to the Mishmi Hills. For some years I have been botanizing on the North-east Frontier of India and on the trans-frontier ranges in Tibet and China which surround the back-door to India, always in the hope of throwing light on a certain purely academic problem, which may be stated thus :

What happens to the Great Himalayan range after the Dihang- Tsangpo has drilled a passage through it, to form one of the greatest gorges in the world ? Does it, like the river, turn round on itself and trend, if not west, at any rate south ? Or does it continue in a general easterly direction ?

Geographers and geologists have tried to solve that problem, the former by plotting the lines of highest peaks, the latter by determining the sequence of the rocks, their age, and strike. But it is possible that the botanist also will eventually have something to say, which will help to unfold the history of a feature unique on the earth's surface—a series of big rivers converging from widely-separated sources, flowing at different levels along closed parallel lines, in deep gorges, and after two hundred miles, separating widely again. That is the feature which we find east of the Tsangpo, and which has either turned the Himalayan axis or smothered it. Thus it was that, the permission of Government having been obtained, a trip into the Mishmi Hills was only the last of a sequence of expeditions to penetrate, from every possible angle, the mountain barrier between the plains of India and the Sino-Tibetan tablelands, from Sikkim to Yunnan.

In 1926 I had my first experience of the Mishmi Hills, travelling from Burma to Assam by the route Myitkyina—Putao (Fort Hertz)— Nam Tamai—Seinghku—over the Diphuk La or Talok Pass (14,280 ft.) to the Lohit just below Bima ; thence down the Lohit to Sadiya, In the course of this journey I was able to extend our botanical knowledge of these mountains, and amongst several unexpected discoveries, apart from many new species, I discovered plants hitherto known only from Sikkim, as far east as the sources of the Irrawaddy (e g., Primula Wattii), and others hitherto known only from Yunnan, as far west as the Irrawaddy-Brahmaputra (Lohit) divide (e.g., Primula Agleniana).

This 1926 journey paved the way for my Mishmi Hills expedition of 1928, which was financed by the Percy Sladen Memorial Fund_? and privately. I had seen that the Lohit valley, where the river flows south to Minzong, some miles below Bima, was filled with pine-forest (P. Khasya), instead of the usual Indo-Malayan jungle ; and this though the general altitude of the valley floor is only 3,000 to 4,000 feet. From Bima northwards, indeed, the climate is so dry that no trees at all grow at the bottom of the gorge. Further down-stream the pressure of the Indo-Malayan jungle gradually makes itself felt, so that even before the Lohit swings round to the west to reach the plain of Assam, pines are becoming rarer, and broad-leafed trees more common ; and for the last fifty miles of its course in the mountains, its valley is filled with typical Indo-Malayan jungle comparable to that of the sub-Himalayan tract generally.

Before the Lohit reaches the plains, however, another stream, the Delei, joins it from the north ; and I argued that, just as by travelling northwards up the main valley, one soon entered drier country, covered first with pine-woods, and then still further north with xerophytic scrub, so too by following up the Delei valley one ought to reach the pine-country. The mouth of the Delei is only five marches from Denning, an outpost at the foot of the Mishmi Hills, 45 miles from Sadiya, and connected with it by a dry-weather motor-road; and the valley is thickly populated. It seemed therefore an ideal route into the pine-country.

Lieut. Hardcastle and a surveyor had been up the Delei valley in 1912, and had mapped it to its head. Unfortunately in his report he had said nothing about the vegetation, or if he had, it was suppressed in the general report of the survey operations, which was unfortunate, because a bare statement such as " the valley is filled with dense evergreen forests of broad-leafed trees, with conifers above 7,000 feet, and grows narrower towards its head " would have told the naturalist a great deal.

Hardcastle was no longer available, and thus the one man who might have given me valuable information could not be traced ; so I had to gamble on two things, namely, that the upper Delei valley, like the Lohit, was pine-clad, and that the head of the valley was ice- worn, and widened out into more or less of an amphitheatre, just as the Seinghku valley did. This hope was not unreasonable, for the mountains at the head of the Seinghku valley are not much higher than those at the head of the Delei, and all these spurs are in contact with the same high snowy ranges to the north.

If my surmise was correct, we ought to have no difficulty in reaching the head of the valley, and getting in touch with the main stream of the Himalayan Alpine flora ; if it was not correct, there might be difficulties. At the end of February 1928, my companion, Mr. H. M. Clutterbuck, and I left Sadiya for the Lohit valley ; we got back to Sadiya on November 2, having been eight months in the Mishmi Hills. During this time we collected many hundreds of species, and although it is impossible to give more than general conclusions, based on work in the field, until the collection has been carefully worked out, the results arrived at may be briefly stated thus :

1. The Delei river is a small side-stream which does not rise on the southern flank of the main range, but on a spur of the main range.
2. The valley has never been glaciated ; it is entirely water- worn. The head of the valley is not an open cirque, but grows narrow and deeper, the river flowing in a forested gorge almost from its source.
3. The lower part of the valley, up to the 4,000-foot contour at least, is filled with Indo-Malayan jungle ; the middle and upper forest is composed largely of trees commonly met with on the southern flanks of the Himalaya from Nepal eastwards.
4. The mountains over 15,000 feet high are rich in Alpines, some of which are found in the Himalaya to the west, and others in the mountains of far Upper Burma and Yunnan to the east, but always south of a line drawn roughly through the high peaks of the Himalaya and prolonged eastwards in the same general direction. Many of the Alpine and sub-Alpine plants collected are, however, new species and are probably endemic in the Mishmi Hills (i.e., not found outside a restricted area).
5. At the bottom of the valley, in the river-bed, the rocks are slates and schists, tilted on edge, with a general strike which appears to be north ; possibly however the strike is north-west—south-east. On the higher ranges the rocks are composed of granite and schist, giving rise to very tenacious soils containing a considerable proportion of clay. There was no limestone.

The types of vegetation met with are similar to those encountered on the south flank of the Himalaya and throughout the wet zone to the east, from the Dihang gorge to the Salween. They may be tabulated as follows :—

2,000-6,000 feet.—Indo-Malayan jungle and sub-tropical forest, predominantly evergreen. Cultivation in the valleys. An interesting species of Podocarpus was met with here-the only conifer. Rhododendron arboreum and a few others.

6000-8,000 feet,—Temperate rain-forest. About 50 per cent, deciduous broad-leafed trees, including Magnolia rostrata. The only common conifer is a species of Tsuga, which forms much of the forest at 8,000 feet. Many oaks, Araliaceae, and Bush-rhododendrons; Magnolia globosa.

8,000-10,000 feet.—Rhododendron-Conifer forest. The conifers are Tsuga, Juniperus, Larix Griffithii, and Taxus baccata. Big- leafed tree-rhododendrons abound, growing gregariously and often forming 50 per cent, of the forest trees. The deciduous trees are Betula sp., species of Acer (including A. pictum), Gamblea ciliata, species of Pyrus (Crab Apple), etc. Evergreen broad-leafed trees include, besides rhododendrons, several species of Cinnainomum, Illicium, etc. There is a lot of bamboo undergrowth in this belt.

10,000-12,000 feet.—Abies-Rhododendron forest. Here Abies Webbiana grows socially, forming 80 per cent, or more of the forest The only other big tree is Larix Griffithii. The rhododendrons, which, occur in great variety, are for the most part large shrubs or bushes forming a dense tangled undergrowth ; most of the species grow socially.

12,000-13,000 feet.—Rhododendron scrub and Alpine meadow. The former is found on the more sheltered slopes, the latter on exposed slopes. In the meadow occur species of Nomocharis, Primula, Anemone, Strobilanthes, Polygonum, Lloydia, Rheum, etc. With the dwarf-rhododendrons are found species of SaZisc, Cassiope, Berheris, Juniperus, Ilex Pernyi, etc.

Above 13,000 feet,—Above 13,000 feet the vegetation becomes scanty. It consists of scattered alpines, scree plants, occasional dwarf rock-rhododendrons such as 22. repens, and alpine turf. Meconopsis paniculata was found here. Above about 14,500 feet vegetation virtually ceases, though the actual snow-line lies considerably higher.

Taking the above belts in more detail, one may say that the lower forest does not differ materially from that found in other parts of Assam and the sub-Himalayan tract generally. Common trees are :— Lagerstroemia par viflora, Elceocarpus serratus, Castanopsis indica, Engelhardtia spicata, Derris robusta, Ficus Cunia_} Albizzia Julibrissin, Pterospermum acerifolmin, Bischofia javanica, and Altingia excelsa; and at higher levels, Cornus Nuttallii, Corylopsis himalayana, Rhododendron Mackenzianum, R. Nuttallii, etc. Between 6,000 and 8,000 feet is the highest belt of mixed broad-leafed forest. It may be remarked that in the Mishmi Hills there are no gregarious forests of broad-leafed trees—nothing corresponding to, say, the beech-forests of Europe, or even to the Sal-forests of India and Burma. Typical trees, in addition to those already mentioned, are Bucklandia populnea and Quercus semiserrata. The first gregarious conifer, Tsuga Brunno- niana (?) is met with here. There are many ground-orchids of the genus Phajus, as well as epiphytic or rock-orchids such as Cymbidium and Dendrobrium. Epiphytic shrubs abound, including Rhododendron dendricola; but these reach their greatest development in the next belt.

The Rhododendron-Conifer forest is a region of perpetual moisture, and all the trees are swathed in moss and loaded with epiphytic Ericaceae and other shrubs. The forest is open with comparatively little undergrowth, and that mostly bamboo with small shrubs and Monocotyled onous herbs.

Higher still the forest is composed almost entirely of Abies Webbiana, but though these trees grow comparatively far apart, the forest is often impenetrable, because of the dense thickets of rhododendron.

Finally there is the true alpine belt, above the tree-line. About half the species of rhododendron discovered, grew here ; also there is a larger proportion of new species of alpines than in any other belt.

Above 14,000 feet there is very little vegetation.

Birds of all kinds were extraordinarily numerous in the forests throughout the summer. Owls, woodpeckers, magpies, laughing thrushes, bulbuis, honeysuckers and many others were seen. There were green pigeon in the valley, and woodcock nesting at 13,000 feet, in July ; in October I saw flocks of Tibetan sand grouse in the snow ; blood-pheasants and Monal pheasants occur on all the higher ranges ; and in 1926 I obtained a fine new Trogon on the Burma side of the Diphuk La, and, therefore, technically outside the Mishmi Hills, but in the same general area.

Many of the birds are migrants, coming up to the forests when the rhododendrons are in bloom, in April, May and June. In the autumn they disappear, their place being taken by birds from the snow-clad ranges to the north, which feed on the innumerable berries.

Takin, gooral, bear, monkeys, and other animals are fairly common ; but it must be remembered that, except in the summer when these animals ascend above the tree-line, the mountains are so precipitous and the forest so thick that it is almost impossible to shoot anything except by a fluke. Certainly the Mishmi Hills are not a sportsman's paradise. The Mishmis hunt musk-deer, which appear to be rather plentiful, and there are barking-deer in the valleys.

For the benefit of future travellers it may be remarked that the Taroan Mishmis, beyond the administered line, are difficult to manage. They are grossly lazy and dislike cooly work, and they are childish and dishonest in a feeble way. Petty larceny is their strong suit ; but mutual suspicion and a yellow streak would probably prevent them ever indulging in a serious ⁴⁶ hold-up " of the white man or the Tibetan, especially if they could gain their ends by non-co-operation as they did with us. Most of them—not all—take opium in excess ; but as every village and almost every hut grows its own crop, nothing is gained by carrying opium for payment. They have hazy ideas of the value of money, the more remote inhabitants of the Delei valley rarely visiting Sadiya. Unlike the Abors, they do not drink much liquor ; in fact above Minutang (Chibaon on the map) no liquor is brewed, though the Mishmis are said to indulge in wild alcoholic orgies when they go down to the plains.

The young men are truculent but easily cowed ; indeed they may be said to be somewhat timid swashbucklers, and the least display of force is enough to frighten them. The Gams have only a nominal Botanical Exploration of the Mishmi Hills control, but we found that when they promised to do a thing, they usually did it ; the difficulty was to make them promise anything.

There is very little traffic over the pass at the head of the Delei valley, a few Mishmis going over to the Kongto Chu, (Rong Thod on map) in the summer to buy salt and cattle, and a few Tibetans coming over in the winter on their way to Sadiya. It is said that the Chulikata Mishmis come across from the headwaters of the Dibang to hunt in the neighbourhood of the Glei Dakhru, and sometimes raid the Taroan villages ; and that the Taroans have a wholesome dread of the Chulikatas. Be that as it may, very few Mishmis go to the head of the Delei valley, and when they do, it may sometimes be to steal cattle from the Tibetan settlements on the other side.

The native hunters are very jealous of their reserves, each village having its own special hunting-ground ; all the villages, however, do not hunt. The chief animals sought are gooral, musk-deer and pheasants, and they are all trapped. Very few of the Taroans have guns— unless at the time we were there they had traded them to the Abors, who were carrying on clan warfare in the Dihang valley.

The only possible routes out of the valley are the hunters' tracks up the ridges to the alpine region below the highest peaks. There are a number of caves along these trails, but at certain seasons it is difficult to find water. It is quite impossible to follow up any of the side streams, most of which drop over a series of precipices ; in any case they are all roaring torrents rushing through narrow glens which are choked with jungle. When we first went to the Delei valley we paid our coolies at the rate of a rupee a day ; but before we left we were paying as much as four rupees a day—and could not always get coolies at that!

The marches from the administered frontier are as follows :— From Theronliang bungalow, on the Tidding river, to Delei river, three marches. The first camp, on the path high above the Lohit, is bad. On the second night one camps on a sandbank, in a bay of the Lohit—a delightful spot, with good fishing. On the third night, camp is pitched in a meadow just below the old bridge over the Delei, on the left bank of the river. From Delei Pani to Minutang (Chibaon) it is two long troublesome marches, camp on the first night being in the river-bed.

 

Minutang to Mitonmna—a short march.

 

Mitonmna to Meiliang—a long march. Camp by the torrent in a meadow by the path, a mile above the village.

 

Meiliang to Petai (Tablehon on the map). A long march, but not difficult in the dry season.

Petai to the rope-bridge—a short but difficult march. In the cold weather afoot-bridge is thrown across the river, but this is washed away by May. Good camping-grounds on both sides of the river.

From the rope-bridge to Cha Che—a ledge of rock on a cliff-face- is under two hours' march for laden coolies. Cha Che was our furthest point up the Delei. From here the path climbs 2,000 feet, and about 5 miles further on descends to the river again, where there is a good open camping-ground. From there to the Glei Dakhru (12,820 ft.) is about two marches

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