STUDIES ON THE FLORISTICS OF THE TROPICAL PLANTS IN JIANGXI

Jiangxi Province is located in the southeast of China, in which it has an ancient geological history and advantageous physiography conditions Its flora wasn't suffered danger by the glacier during the Quaternary. Therefore, a great number of acient tropical elements have been conserved in the flora. Tropical spermatophytes include 95 families, 472 genera and about 1730 species, of which genera can be divided into 6 distribution types(Table 1).Based on statistics and analysis of various distribution types, some floristic characteristics of tropical plants in Jiangxi can be concluded as that: (1)Geographical elements are very complex. The flora is related extensively to the others. The elements of Pantropic and Tropical Asia are possessed of the dominant position. (2)Disjunctive patterns are numerous and the relic plants are very rich. (3)The flora converges and transits from south subtropics to north subtropics in China. Jiangxi is the north border of many elements of tropical flora.This paper preliminarily studies the floristic regionalization of Jiangxi. The author's view is that the demarcation line between the region of South China and the region of East China, in the flora, should be from latitude 25°N (West) to 25°20′N. (East), the demarcation line of the flora between the mid-subtropical region and the north subtropical region should be from latitude 29°N. (West) to 29°40′N. (East), and the demarcation line of the flora between the south subregion and the north subregion of the mid-subtropical region should be from latitude 27°N (West)to 27°40′N. (East), within the extent of Jiangxi Province. Three demarcation lines tend towards gradually lifted from west to east, which is due to the influence of the monsoon climate of the Pacific Ocean.