陕西留坝地区种子植物区系分析

陕西留坝地区有种子植物１３３科、６３５属、１４８０种。本文对该地区植物区系进行了统计分析。统计分析结果表明：（１）本地区种子植物种类丰富，共有裸子植物６科、１３属、１９种；单子叶植物１８科、１３５属、２９７种；双子叶植物有１０９科、４８７属、１１６４种。木本种类５６６种，占３８．２％，草本９１４种，占６１．８％。（２）属的地理分布类型种类多，１５个分布类型及１５个变型。其中温带成分占６７．０％，有

A FLORISTIC ANALYSIS OF THE SEED PLANTS IN LIUBA REGION OF SHAANXI PROVINCE

This paper deals with the floristic statistics and analysis of the Liuba region in South Shaanxi Province.Based on the statistics and analysis,the results show that 1480 seed plant species including subspecies and varieties were found in this region.These species belong to 635 genera in 133 families including 6 families,13 genera and 19 species of gymnosperms;18 families,135 genera and 297 species of monocotyledon;109 families,487 genera and 1164 species of dicotyledon.There are 15 distribution type of genera of seed plants and 15 subtype in the region.The florastic analysis indicated that the whole genera are the temperate character principal which occupied 67.0% and the tropical elements occupied 28.5%.Besides,this region occupied a large proportion of archaic,relic and primitive plants,and have rare endangered plant 18 species,the chinese endemic genera 26 genera.The analysis results explained the ancient characteristics of historical origion and the transitional characteristics from temperate zone to subtropical zone in Liuba region.So,Liuba flora is one of the important composition area of the Qinling plant flora.