A Naturalist In Western ChinaE. H. Wilson

The Flora Of Western China

Part 2 of excerpts from E. H. Wilson’s A Naturalist In Western China, vol. 2 entitled The Flora Of Western China – A Brief Account Of The Richest Temperate Flora In The World, being Chapter 1 of volume 2. This excerpt covers the wealth of flora that he encountered in Western China where he did much plant-hunting over a dozen years or so early in the 20th century. He also helps to clear up some of the confusion engendered by such a profusion of flora that is to be encountered in China and illustrates what a significant effect it has had on Western gardening.

Jim Thorleifson

A NATURALIST IN WESTERN CHINA (1913)

E. H. Wilson (1876 – 1930)

CHAPTER I

THE FLORA OF WESTERN CHINA

A Brief Account Of The Richest Temperate Flora In The World

In previous chapters the wildly mountainous character of Western China has been emphasized. Such a region, affording, as it does, altitudinal extremes, a great diversity in climate, and a copious rainfall, is naturally expected to support a rich and varied flora. Yet after making every allowance for the favourable conditions that obtain in this region the wealth of flowers which meets the eye of the botanist is astonishing and surpasses the dreams of the most sanguine. Competent authorities estimate the Chinese flora to contain fully 15,000 species, half of which are peculiar to the country. These figures speak for themselves and yet fail to give a truly adequate idea of the profusion of flowers. The remote mountain fastnesses of central and Western China are simply a botanical paradise, with trees, shrubs, and herbs massed together in a confusion that is bewildering. On first arriving in a new and strange country it is difficult to recognize the plants one is familiar with under cultivation, and many months necessarily elapse before one is in any sense familiar with the common plants around him. During the eleven years I travelled in China I collected some 65,000 specimens, comprising about 5000 species, and sent home seeds of over 1500 different plants. Nevertheless, it was only during the latter half of this period that I was able to form an intelligent idea of the flora of China and to properly appreciate its richness and manifold problems.

The Chinese flora is, beyond question, the richest temperate flora in the world. A greater number of different kinds of trees are found in China than in the whole of the other north-temperate regions. Every important genus of broad-leaved trees known from the temperate regions of the Northern Hemisphere is represented in China except the Hickory (Carya), Plane (Platanus), and False Acacia (Robinia). All the coniferous genera of the same regions, except the Redwoods (Sequoia), Swamp Cypress (Taxodium), Chamaecyparis, Umbrella Pine (Sciadopitys), and true Cedars (Cedrus), are found there. In North America, excluding Mexico, about 165 genera of broad-leaved trees occur. In China the number exceeds 260. Of the 300 genera of shrubs enumerated in the Kew Hand-List of Trees and Shrubs (1902 ed.) fully half are represented in China.

The great interest and value, however, of the Chinese flora lies not so much in its wealth of species as in the ornamental character and suitability of a vast number for the embellishment of parks and outdoor gardens throughout the temperate regions of the world. My work in China has been the means of discovering and introducing numerous new plants to Europe and North America and elsewhere. But previous to this work of mine the value of Chinese plants was well known and appreciated. Evidence of this is afforded by the fact that there is no garden worthy of the name, throughout the length and breadth of the temperate parts of the Northern Hemisphere, that does not contain a few plants of Chinese origin. Our Tea and Rambler Roses, Chrysanthemums, Indian Azaleas, Camellias, Greenhouse Primroses, Moutan Paeonies, and Garden Clematis have all been derived from plants still to be found in a wild state in central and Western China. The same is true of a score of other favourite flowers. China is also the original home of the Orange, Lemon, Citron, Peach, Apricot, and the so-called European Walnut. The horticultural world is deeply indebted to the Far East for many of its choicest treasures, and the debt will increase as the years pass.

Our knowledge of the marvellous richness of the Chinese flora has been very slowly built up. Travellers, missionaries of all denominations, merchants, consuls, Maritime Customs officials, and all sorts and conditions of men have added their quota; but, as in geography and other departments of knowledge relating to the Far East, the Roman Catholic priests have played the prominent part. The exclusive policy of the Chinese has necessarily increased the difficulties of Europeans who sought to acquire an intimate knowledge of the country, and all honour is due to the workers who have exploited this field in the past.

On behalf of the Royal Horticultural Society of London and others, Robert Fortune, in the ‘Forties and ‘Fifties of last century, completed the work of his predecessors and exhausted the gardens of China, to our gardens’ benefit; but the difficulties of travel were such that he had practically no opportunity of investigating the natural wild flora. With the exception of perhaps half a dozen plants, everything he sent home came from Chinese gardens. But one of his wildlings — Rhododendron Fortunei, to wit — has proved of inestimable value to Rhododendron breeders.

Charles Maries, collecting on behalf of Messrs. Veitch, in 1879, ascended the Yangtsze as far as Ichang. He found the natives there unfriendly, and after staying a week was compelled to return. During his brief stay, however, he secured Primula obconica, one of the most valuable decorative plants of to-day. Near Kiukiang he secured Hamamelis mollis, Loropetalum chinense, and a few other plants of less value, and then hied himself away to Japan. For some curious reason or other he concluded that his predecessor. Fortune, had exhausted the floral resources of China, and, most extraordinary of all, his conclusions were accepted! When at Ichang, could he but have gone some three days’ journey north, south, or west, he would have secured a haul of new plants such as the botanical and horticultural world had never dreamed of. By the irony of Fate it was left for two or three others to discover and obtain what had been almost within his grasp.

The enormous Chinese population, especially in the vicinity of the Lower Yangtsze, and its vast alluvial delta and plains, no doubt mizzled Maries, as it has done others. So densely is China populated that every bit of suitable land has been developed under agriculture. A Chinese is capable of getting more returns from a given piece of land than the most expert agriculturist of any other country. Dry farming and intensive cultivation, though unknown to the Chinese under these terms, have been practised by them from time immemorial. The land is never idle, but is always undergoing tilling and manuring. Nevertheless, in spite of the almost incredible industry of the Chinese cultivator, much of the land in the wild mountain fastnesses of central and Western China defies agricultural skill, and it is in these regions that a surprisingly varied flora obtains. These regions are very sparsely populated, are difficult of access, and, until comparatively recently, were totally unknown to the outside world.

The botanical collections of the two French Roman Catholic priests, les Abbès David and Delavay, of the Russian traveller, N. M. Przewalski, and of the Imperial Maritime Customs officer, Augustine Henry, gave the first true insight into the extraordinary richness of the flora of central and Western China. Delavay’s collection alone amounted to about 3000 species, and Henry’s exceeded this number! Botanists were simply astounded at the wealth of new species and new genera disclosed by these collections. An entirely new light was thrown on many problems, and the headquarters of several genera, such as, for example, Rhododendron, Lilium, Primula, Pyrus, Rubus, Rosa, Vitis, Lonicera, and Acer, heretofore attributed elsewhere, was shown to be China.

This extraordinary wealth of species exists, notwithstanding the fact that every available bit of land is under cultivation. Below 2000 feet altitude the flora is everywhere relegated to the roadsides, the cliffs, and other more or less inaccessible places. It is impossible to conceive the original floral wealth of this country, for obviously many types must have perished as agriculture claimed the land, not to mention the destruction of forests for economic purposes.

In order to summarize the account of this wonderful flora it is convenient to divide the region into altitudinal zones or belts. The mountainous nature of the country lends itself admirably to such an arrangement, and it is perhaps the only feasible way of dealing with a subject so vast and unwieldy. The chart (p. 7) represents an ideal section of the region and may possibly convey a clearer idea of the subject than the text which follows: —

Division 1. — ” The belt of cultivation — 2000 feet altitude.” The climate of the Yangtsze Valley, up to 2000 feet altitude, is essentially warm-temperate. Rice, cotton, sugar, maize, tobacco, sweet potatoes, and legumes are the principal summer crops; in winter, pulse, wheat, rape, hemp, Irish potato, and cabbage are generally grown. It is a region of intense cultivation and the flora is neither rich nor varied. The following wild plants are characteristic: Bamboos (Bambusa arundinacea, Phyllostachys pubescens, and other species) , Fan Palm(Trachycarpus excelsus), ” Pride of India ” (Melia Azedarach), Crepe Myrtle (Lagerstramia indica), Winter Green (Xylosma racemosum, var. pubescens), Chinese Banyan (Ficus infectoria), Gardenia (Gardenia florida), Roses (Rosa Iaevigata and R. microcarpa) , Nanmu (Machilus nanmu and other species). Pine (Pinus Massoniana), Soap tree (Gleditsia sinensis), Alder (Alnus cremastogyne) , Privet (Ligustrum lucidum), Paulownia Duclouxii, oranges, peaches, and other fruit trees, ferns, especially Gleichenia linearis, weeds of cultivation, miscellaneous shrubs and trees, including Pterocarya stenoptera, Celtis spp., Caesalpinia sepiaria, Wood Oil (Aleurites Fordii), and Cypress (Cupressus funebris); the last two occurring particularly in rocky places.

Division 2. — ” Rain forests belt — 2000 to 5000 feet altitude.” Between 2000 and 5000 feet are found rain forests, consisting largely of broad-leaved evergreen trees, mainly Oak, Castanopsis, Holly, and various Laurineae. The latter family constitutes fully 50 per cent, of the vegetation in this zone. Ferns, evergreen shrubs, Chinese Fir (Cunninghamia lanceolata), and Cypress are other prominent components. This belt is interesting also as being the home of nine-tenths of the monotypic genera of trees that are so prominent a feature of the Chinese flora. The more interesting of these are: Eucommia, Itoa, Idesia, Tapiscia, Sinowilsonia, Platycarya, Davidia, Carrieria, Pteroceltis, and Emmenopterys. Cultivation is less general in this region, and the winter crop especially is of less importance. The crops are similar to those of the belt below except that maize is the staple and displaces rice. In Hupeh this zone is much less extensive and can hardly be said to exist when comparison with its development in western Szechuan is made.

Division 3. — ” Cool-temperature belt — 5000 to 10,000 feet altitude.” From 5000 to 10,000 feet is the largest and most important zone of all. It is composed principally of deciduous flowering trees and shrubs characteristic of a cool-temperate flora and belonging to familiar genera. To these must be added forests of Conifers and many ornamental tall-growing herbs. It is in this zone that is found the astonishing variety of flowering trees and shrubs so pre-eminent a feature of this flora: of Clematis 60 species are recorded from China; of Lonicera, 60; of Rubus, 100; of Vitis, 35; of Euonymus, 30; of Berberis, 50; of Deutzia, 40; of Hydrangea, 25; of Acer, 40; of Viburnum, 70; of Ilex, 30; of Prunus, 80; of Senecio, 110; and the enumeration might be further extended. Pyrus (including Malus, Sorbus, Micromeles, and Eriolobus) is a prominent family in the belt, and behaves in China in the same manner as Crataegus does in the United States of America.

Amongst such botanical wealth it is difficult to make selections, but if any one genus has outstanding claims it is Rhododendron. As in the Himalayan region, so in Western China, the Rhododendrons are a special feature. The genus is the largest recorded from China, no fewer than 160 species being known. I, myself, have collected about 80 species and have introduced upwards of 60 into cultivation. Rhododendrons commence at sea-level, but do not become really abundant until 8000 feet is reached. They extend up to the limits of ligneous vegetation (15,000 feet, circa). These plants are gregarious in habit and nearly every species has a well-defined altitudinal limit. In size they vary from alpine plants only a few inches high to trees 40 feet and more tall. The colour of their flowers ranges from pure white, through clear yellow to the deepest and richest shades of scarlet and crimson. In late June they are one mass of colour, and no finer sight can possibly be imagined than mile upon mile of mountain-side covered with Rhododendrons in full flower.

Division 4. — ” Temperate alpine belt — 10,000 to 11,500 feet altitude,” Above 10,000 feet in Western China the character of the flora undergoes a great change, and the narrow belt between 10,000 and 11,500 feet forms the hinterland between the temperate and alpine zones. This narrow belt is mostly moorland, but where the nature of the country admits, magnificent forests occur. The moorlands are covered with dwarf, small-leaved Rhododendrons and scrub-like shrubs, chiefly Berberis, Spiraea, Caragana, Lonicera, Potentilla fruticosa, P. Veitchii, and Hippophae salicifolia, with Willow, prickly Scrub Oak, coarse herbs, grasses, and impenetrable thickets of dwarf Bamboo. The forests are composed almost exclusively of Conifers, chiefly Larch, Spruce, Silver Fir, Hemlock Spruce, and here and there Pine. A few trees of Red and White Birch and Poplar occur, chiefly near streams. Specifically very little is known about the constituents of these forests, but, to illustrate their wealth, I may mention that on my last journey I collected seeds of some 16 different species of Spruce and 5 of Silver Fir. These forests are, unfortunately, fast disappearing, and are only to be found in the more inaccessible regions. The tree-limit varies according to rainfall, and may be put down as between 11,500 and 12,500 feet.

Division 5. — ” The alpine belt — 11,500 to 16,000 feet altitude.” The alpine zone extends from 11,500 to 16,000 feet. The wealth of herbs in this belt is truly astonishing. Their variety is wellnigh infinite, and the intensity of the colour of the flowers is a striking feature. The genus Pedicularis (Louseworts) , with 100 species, is perhaps the most remarkable constituent. The Louseworts are largely social plants and occur in countless thousands, their flowers being all colours save blue and purple. They are really most fascinating plants, and it is a great pity that their semi-parasitic nature prevents their cultivation. The Ragworts (Senecio), with 100 species, have yellow flowers, and the plants vary in size from low cushion-like plants to strong herbs 6 feet tall. Blue is supplied by the Gentians (Gentiana), of which there are 90 species. These again are social plants, and on sunny days the ground for miles is often nothing but a carpet of Gentian flowers of the most intense blue. The Fumeworts (Corydalis), with 70 species, supplies both yellow and blue flowers and cannot be denied a place. Then there are the wonderful alpine Primroses (Primula). This family is represented in China by some 90 species, four-fifths of which occur in the west. These, like Gentians, take unto themselves in season large tracts of country and carpet them with flowers. Sometimes it is a marsh, at other times bare rock or the sides of streams. One of the most beautiful is Primula sikkimensis. Along the sides of streamlets and ponds this species is as common as the Cowslip in some English meadows. Associated with it is its purple congener P. vittata. Other striking species are P. Cockburniana, with orange-scarlet flowers, a colour unique in the genus; P. pulverulenta, a glorified P. japonica, with flower-scapes 3 to 4 feet tall, covered with a white meal and flowers of a rich purple colour; and P. Veitchii, which is best described as a hardy P. obconica. Other striking herbs are Incarvillea compacta and I. grandiflora, both with large scarlet flowers, and Cypripedium tibeticum, a terrestrial orchid with enormous pouches, dark red in colour. Also we have Meconopsis in half a dozen species, including M. Henrici, with violet-coloured flowers; M. punicea, with dark scarlet flowers; and M. integrifolia, with yellow flowers 8 inches or more across – possibly the most gorgeous alpine plant extant.

Division 6. — ” High alpine belt.” The limit of vegetation is about 16,500 feet; a few cushion-like plants belonging to Caryophyllaceae, Rosaceae, Cruciferae, and Compositae, with a tiny species of Primula and Meconopsis racemosa being the last to give out. Above this altitude are vast moraines and glaciers, culminating in perpetual snow. The snow-line cannot be less than 17,500 feet. Although at first sight remarkable, the high altitude of the snow-line is easily accounted for by the dryness of the Thibetan plateau and the highlands to the immediate west.

Having briefly outlined the different altitudinal zones and instanced some of the more striking plants characteristic of each, it may be of interest to point out the more important absentees. In China there is no Gorse (Ulex), Broom (Cytisus), Heather (Erica), nor Ling (Calluna); the Rock-rose family (Cistus and Helianthemum) is also unrepresented. The place of Gorse and Broom is inadequately taken by Forsythia, Caragana, Berberis, and various Jasmines; that of Heather by dwarf, tiny-leaved Rhododendrons, of which there are a dozen or more species. The Cistus family has no representative group unless Hypericum be considered its substitute.

There is practically no pasture-land in central and Western China, but such open country as would compare with commons in England is covered with bushes of Berberis, Spiraea, Sophora viciifolia, Caragana, Pyracantha, Cotoneaster, Philadelphus, Holly, and various Roses. The anomalous conditions obtaining in the river-valleys of the west and the peculiar flora found there have been described in Vol. I, Chapter XII.

Another interesting fact, and one that has peculiar reference to the flora of western Hupeh, is the number of plants bearing the specific name japonica, which are only Japanese by cultivation and are really Chinese in origin. The following well-known plants are examples: Iris japonica, Anemone japonica, Lonicera japonica, Kerria japonica, Aucuba japonica, Senecio japonicus, and Eriobotrya japonica. Possibly some of these (and there are many more) may be common to both countries, but I am convinced that when the subject is properly worked out, it will be found that fewer plants are common to both countries than is generally supposed to be the case.

The Chinese flora is largely peculiar to the country itself, the number of endemic genera and species being remarkable even when the size of the country is given due consideration. Yet, in spite of its generally local character, the Chinese flora presents many interesting problems in plant distribution. Not the least interesting is to account for the presence of a species of Libocedrus (L. macrolepis), seeing that the other members of this genus are found in California, Chili, and New Zealand. Another noteworthy feature is a species of Osteomeles (0. Schwerinae), which occurs in the far west of China, the other member of this family being found scattered through the islands of the Pacific Ocean. But perhaps the most extraordinary fact in this connexion is the presence on Mount Omei of a species of Nertera (N. sinensis), the other members of this family being purely insular and confined to the Southern Hemisphere.

The affinity of the Chinese flora, with contiguous and distant countries, is an interesting theme and one that could be enlarged upon at length. The Himalayan flora is represented by certain species in Western and central China, and there is a considerable affinity between the floras of these regions. This is to be expected, yet it presents problems of exceptional interest, since it is the Sikhim element which comes out strongest. When the flora of Bhutan and of the country between Bhutan and Western China is properly explored it will probably be found that Sikhim represents the most western point of distribution for certain plants rather than their real headquarters. Of Himalayan plants commonly met with in the region, with which this work is intimately concerned, the following examples may be given: Euonymus grandiflora, Euptelea pleiosperma, Clematis montana, C. grata, C. gouriana, Rosa sericea, R. microphylla, Primula sikkimensis, P. involucrata, Podophyllum Emodi, and Amphicome arguta. In Yunnan there is a decided affinity with the Malay-Indian flora.

The aggressive nature of the Scandinavian (British) flora is evidenced by the following herbs and shrubs which are locally very common: Vervain (Verbena officinalis), Agrimony (Agrimonia Eupatoria), Buttercups (Ranunculus acris, R, repens, and R. sceleratus), Silver-weed (Potentilla anserina). Great Burnet (Poterium officinale), False Tamarisk (Myricaria germanica). Ivy [Hedera Helix), Bird Cherry [Prunus Padus), and Plantain [Plantago major) .

In the north and throughout the upland valleys and highlands of the west a few Central Asian and Siberian forms occur, such as Sibiraea laevigata, Spiraea alpina, Cotoneaster multiflora, Thalictrum petaloideum, Delphinium grandiflorum, and Lonicera hispida.

At first sight it would very naturally be supposed that the Chinese flora was most closely allied if not to that of Europe at least to that of the Asiatic continent generally. Yet this is not so. The real affinity is with that of the Atlantic side of the United States of America!

This remarkable fact was first demonstrated by the late Dr. Asa Gray when investigating the early collections made in Japan. Modern work in China, and especially central China, has given overwhelming evidence and established beyond question Asa Gray’s conclusions. There are many instances in which only two species of a genus are known – one in the eastern United States and the other in China. Noteworthy examples are the Tulip tree, Kentucky Coffee tree, the Sassafras, and the Lotus Lily (Nelumbium). A considerable number of families are common to both countries, and in most instances China is the dominant partner. Usually the U.S.A. have one and China several species of the same genus, but here and there the opposite obtains. Magnolias afford a good illustration of this affinity. This genus, absent from Europe and western North America, is represented by 7 species on the Atlantic side of the North American continent, and by 19 species in China and Japan.

The following brief list still further illustrates this:

SOME GENERA COMMON TO CHINA, JAPAN, AND THE ATLANTIC SIDE OF THE UNITED STATES OF AMERICA

China and Japan

United States of America

Genus

No. of Species

Genus

No. of Species

Magnolia

19

Magnolia

7

Schisandra

10

Schisandra

1

         Itea

5

Itea

1

Gordonia

3

Gordonia

2

Hamamelis

2

Hamamelis

2

Shortia

3

Shortia

1

Catalpa

5

Catalpa

2

Negundo (Acer)

5

Negundo (Acer)

1

Wisteria

4

Wisteria

2

Astilbe

10

Astilbe

1

Podophyllum

6

Podophyllum

1

Illicium

6

Illicium

2

Stewartia

2

Stewartia

2

Berchemia

8

Berchemia

1

Nyssa

1

Nyssa

4

In a few cases the same species is common to both countries. The most extraordinary instance of this is Diphylleia cymosa (Umbrella Leaf). This plant occurs in localities separated by 140° of longitude and exhibits absolutely no marked variation.

In the instances mentioned above, the families are absent from any other region in the world. In others,  – for example, Oak, Hornbeam, Elm, Birch, Ash, Beech, and Sweet Chestnut, – where the families range around the whole temperate zone of both Old and New Worlds, the individual Chinese species are usually more closely akin to those of North America than to those of Europe.

The explanation of this phenomenon is to be found in the glaciation of the Northern Hemisphere in prehistoric times. In those far-off times the land connexion between Asia and North America was far more complete than it is to-day, and the flora extended much farther to the north. The ice-cap which gradually crept down forced the flora to travel towards the equator. Later, when the period of great cold was over, and the ice-cap receded, the plants crept back; but the ice-cap remained at a more southern latitude than before, and consequently rendered much of the land formerly covered with forests too cold to support vegetable life of any sort. This rearrangement after the Ice Age caused a break between the two hemispheres, and the consequent isolation and cutting off of the floras. Other agencies and factors played a part, but the above explains briefly and roughly why the floras so much alike should to-day be so widely separated geographically.

That the Chinese flora is an ancient one is evidenced by the number of old types it contains. For example, in ancient times. Ginkgo biloba (Maidenhair tree) was found, not only in Asia, but in Western Europe, Northern California, and Greenland, as the fossil remains found in Jurassic beds of these countries testify. To-day it exists only in China and Japan as a cultivated tree, being preserved to us by the Buddhist and other religious communities who plant it in the neighbourhood of their temples. Cycas, Cephalotaxus, Torreya, and Taxus are other old types, but these occur in a wild as well as in a cultivated state in China to-day. Many of the older ferns, such as Osmunda, Gleichenia, Marattia, and Angiopteris, are common in China and widely spread. In speaking of the older ferns it may be of interest to note that Augustine Henry discovered in Yunnan an entirely new genus of Marattiaceae, which has been named Archangiopteris.

From the evidence before us it would appear that the Chinese flora suffered less during glacial times than did that of Europe and North America. This may possibly have been due to the greater continuity of land towards the equator which obtains in Asia as compared with that of the continents of Europe and America.

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