Page:Encyclopædia Britannica, Ninth Edition, v. 11.djvu/872

Rh 832 HIMALAYA temperature requisite for the preservation of the various species are readily found by ascending or descending the mountain slopes, and therefore a greater uniformity of character in trie vegetation is maintained along the whole chain. At the greater elevations the species which are identical with those of Europe become more frequent, and in the alpine regions many plants are found identical with species of the Arctic zone. On the Tibetan plateau, with tlia increased dryness, a Siberian type is established, with many true Sibsrian species and more genera; and some of the Siberian forms are further disseminated, even to the plains of Upper India. The total absence of a few of the more common form} of northern Europe and Asia should also be noticed, among which may be named Tiiia, Far/us, Arbutus, Erica, Azalea, and Cistacece. In the more humid regions of the east the mountains are almost everywhere covered with a dense forest which reaches up to 12,000 or 13,000 feet. Many tropical types here ascend to 7000 feet or more. To the west the upper limit of forest is somewhat lower, from 11,500 to 12,000 feet, and the tropical forms usually cease at 5000 feet. [ lie In Sikun the mountains are covered with dense forest mter of tall umbrageous trees, commonly accompanied by a anges. J ux uriant growth of under shrubs, and adorned with climb ing and epiphytal plants in wonderful profusion. In the tropical zone large figs abound, Terminalia, Shorea (sal), liurels, many Leyuminosfe, Bombax, Artocarpus, bamboos, and several palms, among which species of Calamus are remarkable, climbing over the largest trees; and this is the western limit of Cyc.as and JMyristica (nutmeg). Plantains ascend to 7000 feet. Pandanus and tree-ferns abound. Other ferns, Scitaminece, orchid, and climbing Aroidete are very numerous, the last-named profusely adorning the forests with their splendid dark-green foliage. Various oaks descend within a few hundred feet of the sea-level, increasing in numbers at greater altitudes, and becoming very frequent at 4000 feet, at which elevation also appear Aucuba, Magnolia, cherries, Pyrus, maple, alder, and birch, with many Araliaceai, Hollb Mea, Skimmia, Daphne, Myrsine, Symplocos, and Rubus. Rhododendrons begin at about 6000 feet and become abundant at 8000 feet, from 10,000 to 14,000 feet forming in many places the mass of the shrubby vegetation which extends some 2000 feet above tha forest. Epiphytal orchids are extremely numerous between GOOO and 8000 feet. Of the Conifers, Podocarpus and Pinus longifolia alone descend to the tropical zone; Abies Brunoniana and Smithiana and the larch (a genus not seen in the western mountains) are found at 8000, and the yew and Picea Webbiana at 10,000 feet. Pinus ejcelsa, which occurs in Bhotan, is absent in the wetter climate of Sikim. Inner On the drier and higher mountains of the interior of the ranges. c ] iri in, the forests become more open, and are spread less uniformly over the hill-sides, a luxuriant herbaceous vegeta tion appears, and the number of shrubby Leguminosa*, such as Desmodium and Indigofera, increases, as well as Ranun- culacece, Rosacea 1, Umbelliferce, Labiata?,, Graminea?, Cype- racece, and other European genera. Alpine The alpine flora of Sikim closely resembles that of the and western Himalaya, and so far as generic forms are concerned, Tibetan tj ia t of the alpine regions of Europe and western Asia. lon&amp;gt; The vegetation of the Tibetan region appears on rising above 14,000 feet, and its last representatives reach even to 18,000 feet. Passing to the westward, and viewing the flora of Kumaon, which province holds a central position on the chain, on the 80th meridian, we find that the gradual decrease of moisture and increase of high summer heat are accompanied by a marked change of the vegetation. The Flora of central moun tains. tropical forest is characterized by the trees of the hotter and drier parts of southern India, combined with a few of European type. Among them are Moringa, Bombax, Butea, Anogeissns, Erytlirina, Acacia, Bauhinia, Nauclea, and Ulmus integrifolia. Pinus longifolia descends almost to the level of the plains. Among the more common shrubs are Zizyplius, Adhatoda, Calotropis, Carissa. Ferns are more rare, and the tree-ferns have disappeared. The species of palm are also reduced to two or three, and bamboos, though abundant, are confined to a few species. The outer ranges of mountains are mainly covered with forests of Pinus longifolia, rhododendron, oak, and Pieris. At Naini-tal cypress is abundant. The shrubby vegetation comprises Rosa, Rubus, Indigofera, Desmodium, Berberis, Boelimeria, Viburnum, Clematis, with an Arundinaria. Of herbaceous plants species of Ranunculus, Potentilla, Geranium, Thalictrum, Primula, Gentiana, and many other European forms are common. In the less exposed locali ties, on northern slopes and sheltered valleys, the European forms become more numerous, and we find species of alder, birch, ash, elm, maple, holly, hornbeam, Pyrus, &c. At greater elevations in the interior, besides the above are met Corylus, the common walnut, found wild throughout the range, horse chestnut, yew, also Picea Webbiana, Pimis excelsa, Abies Smithiana, Cedrus Deodara (which tree does not grow spontaneously east of Kumaon), and several junipers. The denser forests are commonly found on the northern faces of the higher ranges, or in the deeper valleys, between 8000 and 10,500 feet. The woods on the outer ranges from 3000 up to 7000 feet are more open, and consist mainly of evergreen trees. The herbaceous vegetation does not differ greatly, genetically, from that of the east, and many species of Primulacea 3, Ranunculacea*, Cruciferce, Labiatcv, and Scropkulariaceoe occur ; balsams abound, also beautiful forms of Campamdacece, Gentiana, Meconopsis, Saxifraga, and many others. Cultivation hardly extends above 7000 feet, except in the valleys behind the great snowy peaks, where a few fields of buckwheat and Tibetan barley are sown up to 11,000 or 12,000 feet. At the lower elevations rice, maize, and millets are common, wheat and barley at a somewhat higher level, and buckwheat and amaranth usually on the poorer lands, or those recently reclaimed from forest. Besides these, most of the ordinary vegetables of the plains are reared, and potatoes have been introduced in the neigh bourhood of all the English stations. As we pass to the west the species of rhododendron, oak, and Magnolia are much reduced in number as compared to the eastern region, and both the Malayan and Japanese forms are much less common. The herbaceous tropical and semi-tropical vegetation likewise by degrees disappears, the Scitaminece, epiphytal and terrestrial Orchidca 1 , Aracece, Cyrtandracea?, and Begonia? only occur in small numbers in Kumaon, and scarcely extend west of the Sutlej. In like manner several of the western forms suited to drier climates find their eastern limit in Kumaon. In Kashmir the plane and Lombardy poplar flourish, though hardly seen further east, the cherry is cultivated in orchards, and the vegetation presents an eminently European cast. The alpine flora is slower in changing its character as we pass from east to west, but in Kashmir the vegetation of the higher mountains hardly differs from that of the mountains of Afghanistan, Persia, and Siberia, even in species. The flora of western Tibet is essentially European in its character. The juniper and poplar are the only trees that are seen, excepting fruit-trees, which include apricot, pear, and grape. The shrubby plants include small forms of willow, elm, Lonicera, rose, Myricaria, Ephedra, and The oute rang fove: Bei lmc&amp;lt; vegi tion Floi mos -cs arei Of wesl Tib&amp;lt;