Page:Flora of Kwangtung and Hongkong.djvu/11

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INTRODUCTION.


Position and size of area.—Kwangtung is the southernmost province of China and occupies the whole of the southern coast line of the empire. Bounding it upon the north are the maritime province of Fokien and the inland ones of Kiangsi and Hunan, while Kwangsi lies immediately to the west. At its south-west corner it touches for a few miles the French Indo-Chinese colony of Tongking. Its length amounts to 600 miles lying nearly east and west, but it nowhere recedes more than 250 miles from the open sea. Its area, about 68,000 square miles, is rather less than that of Great Britain. Some 300 small islands lie off the coast, among which is Hongkong.

Climate.—The province is more than half within the tropics and is characterised for the greater part of the year by hot damp weather, during which periods of strong sunshine alternate with downpours of warm torrential rain amounting to some 70 inches in all. The south-west monsoon, in which these conditions prevail, breaks upon the coast rather suddenly about April and continues to blow with more or less regularity for six or seven months, gradually failing in October or November, to give place to the winter monsoon from the opposite point of the compass. The long succession of rainstorms and the usually cloud-laden sky are then succeeded as a rule by several months of cool weather accompanied by clear pale blue skies and a complete absence of rain. The smaller streams gradually dry up and the grass hills assume their winter colouring of pale brown.

Though the winters are pleasantly cool, frosts are of very rare occurrence, except on the highest ground. Even there they are infrequent and of short duration.

The succession of extremes of wet and dry weather naturally exerts a profound influence on the vegetation, but quite as important in this respect are doubtless the periodical visits of typhoons to which the coastal regions are liable at all times, but especially during the late summer. These brief but extraordinarily violent storms play great havoc with all kinds of vegetation and their occurrence explains some of the peculiar characters of the flora of the coast of Kwangtung.

Geology.—The greater part of the surface of the coastal region consists of various igneous rocks, but chiefly of a kind of granite, which readily disintegrates under the action of the atmosphere. This granite is intermixed with harder and more resistant rock masses, which remain as gigantic boulders all over the granite mountains as the softer parts are washed away. In the interior and to a less extent on the coast, limestone formations, coal measures and tertiary sandstones occupy large areas. Alluvial deposits attain considerable dimensions only in the deltas of the East, West and North Rivers which coalesce to form the "Canton Delta" occupying approximately a triangle having three equal sides of about 100 miles each.

Physical features.—Kwangtung and Kwangsi, as their names imply, form the artificial eastern and western divisions of a natural area, the basin of the great river of South China, the West River. The mountain ranges of Kwangtung, which can be seen from the sea, are(21515—6a.) Wt. 19085—411 (73). 500. 2/12. D & S.