浙江省水鳖科植物的种类与分布

浙江省有水鳖科植物5属8种,均属淡水种类,其中无尾水筛、有尾水筛和密齿苦草为浙江分布新记录。在水平分布上,水筛属分布局限于浙江东南部,苦草属则分布于浙江大部分地区而未见于浙江南部。在垂直分布上,水筛属的种数和分布量,在海拔600米以下,随海拔增高而增加,再向上又有减少的趋势;其余各属的种数和分布量则随海拔增高而减少。它们的分布主要受各自适宜的生境在水平和垂直带的不同分布所制约。浙江水鳖科植物区系与我国亚热带各省区尤其是相邻省的关系十分密切。

CLASSIFICATION AND DISTRIBUTION STUDIES ON HYDROCHARITACEAE FROM ZHEJIANG PROVINCE

In this paper, 5 genera and 8 species of Hydrocharitaceae are recorded. Among them, Blyxa aubertii Rich., B. echinosperma(Clarke) Hook. f and Vallisneria denseserrulata (Makino) Makino are the first to be recorded from Zhejiang Province. As to the horizontal distribution, species of Blyxa Noronha only occur in southeast of Zhejiang, but species of Vallisneria L. are found in wlole province except in the south of Zhejiang. With regard to the vertical distri(?)utien, lelow 600m of altitude, the number of species and the amount of distribution of Blyxa Noronha tend to increase with the increase of altitude, but the/tend to decrease with the further increase of altitude. The number of species and the amount of distribution of the other genera tend to decrease with the increase of altitude. The distribution patterns of Hydrocharitaceae are chiefly related to the habitats of each genus. The flora of Hydrocharitaceae in Zhejiang is closely related with the subtropical areas of China, especially with its adjacent province.