江苏分布的中国种子植物特有属研究

经调查和统计，江苏分布的中国种子植物特有属有18属，含19种，隶属于17个科，科、属、种分别占中国种子植物特有属总数的19.32%、5.61%和2.53%。根据自然地理特征将江苏分为6个地区：黄淮平原、江淮平原、滨海平原、长江三角洲、北部低山丘陵和西南低山丘陵。首次采用特有性指数(EI)研究上述地区的特有属分布，结果发现：EI值最高的是西南低山丘陵（4.83），其次是长江三角洲（3.89），黄淮平原和滨海平原的特有性指数最低（1.67）。因此该区的特有属植物的种类组成较贫乏，地理分布不均，并具有生活型多样，古特有属比例较高等特征。

Study on the Chinese endemic genera of seed plants distributed in Jiangsu Province

By investigation and statistics,we found that there were 18 Chinese endemic genera of seed plants in Jiangsu,containing 19 species, which belonged to 17 families.The percentages of the same group possessing in Jiangsu of China were: 19.32% of 88 families,5.61% of 321 genera,and 2.53% of 751 species.According to its natural geographical features,we divided Jiangsu Province into six regions: Huanghuai Plain,Jianghuai Plain,Binhai Plain,Changjiang Delta,Northern low Massif and Southwest low Massif.It was for the first time that endemic index(EI) was applied to reveal the distribution pattern of the endemic genera in the regions.The result showed that the highest EI among six regions was 4.83,which appeared in Southwest low Massif;the second one was 3.89,which appeared in Changjiang Delta;the lowest one was 1.67,which appeared in Huanghuai Plain or Binhai Plain.The characteristics of Chinese endemic genera of seed plants in Jiangsu were as follows:(1)The floristic composition was relatively poor;(2)The geographical distribution was fairly uneven;(3)Most of these 18 genera,with different life forms,were palaeoendemic genera.