Page:Flora Hongkongensis.djvu/23

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PREFACE.
17*

7. The Temperate Asiatic Flora. South Siberian, Dahurian, Mantchurian, and Japanese plants, which attain their southern limit in Hongkong.

The number of Hongkong species which I would attribute to each of these Floras is given in the following Table. It mast be remembered, however, that these are approximative only, the limits of the areas of species are so vague, their extent so diversified, scarcely two species being ever precisely similar in this respect, that it would be impossible to class them with precision, even were their area always perfectly well known to us.


Table of the Hongkong Species, classed according to their Geographical Areas.
Trees,
shrubs,
or tall
woody
climbers.
Herbs, un-
dershrubs,
or slender
climbers.
Proportion
of woody to
herbaceous
species.
Total
species.
Tropical Asiatic Flora 48 350 1 to 7•292 398
North-east Indian Flora 34 85 1 to 2•500 119
South-east Indian Flora 24 50 1 to 2•083 74
Archipelago and Pacific Flora 20 36 1 to 1•800 56
Chinese Flora 102 85 1 to 0•833 187
Endemic Flora 94 65 1 to 0•691 159
Temperate Asiatic Flora 1 9 1 to 9•000 10
Total 323 680 1 to 2•605 1003

Let these be compared with the Floras of two districts similarly circumstanced as to maritime position and proximity to the mainland, nearly the same in size and elevation above the sea, but widely different as to soil and climate, viz.:—

1. Aden Peninsula, off the coast of Arabia, in lat. 12° 47′. A dry, parched, volcanic, rocky peninsula or almost an island, about 5 miles long by 3 in breadth, the highest peak attaining 1775 ft., and connected with the mainland by a narrow sandy isthmus. It is exposed throughout the year to a scorching sun, occasionally deprived of rain for a year and a half, and never receives an annual fall of above 6 or 7 inches. Winds are not frequent and seldom violent.

2. Ischia Island, off the Neapolitan coast, in lat. 40° 41′. A volcanic rocky mountain mass, nearly 6 miles long by 3½ in breadth, the highest peak attaining 2,407 ft., and about 9 miles distant from the mainland. Hot and dry during the summer months, it is however well refreshed by rains during the remainder of the year. The thermometer very rarely