中文摘要：

对国产水晶兰属植物水晶兰（Monotropa uniflroa L．）和毛花松下兰（M．hypopitys var．hirsutea Roth）的花粉母细胞减数分裂进行了观察，它们的减数分裂中期Ⅰ的染色体数目均为n=24。结合前人所做的研究，确定该属的染色体基数为x=8，并对该属的染色体基数和倍性变异与地理分布区的关系进行了初步探讨。通过对鹿蹄草亚科和水晶兰亚科的染色体基数比较，结合两个亚科的生长习性和花药开裂方式的不同，作者赞同哈钦松系统将水晶兰亚科作为科的处理。

英文摘要：

The chromosome numbers of meiotic metaphase Ⅰ of pollen mother cell of Monotropa uniflroa L. and M. hypopitys var. hirsutea Roth are reported. It is shown that the chromosome numbers in both plants are n = 24. In accordance with previous cytologyical data and our observation, basic chromosome number in Monotropa is x = 8. The variations of ploidy and geographical distribution of taxa of Monotropaceae and Pyrolaceae are discussed. Basic chromosome mumbers in subfamilies Monotropadieae and Pyroloideae were compared. In view of the differences in growth habit and anther splitting in the two subfamilies, the authors agree with Hutchinson, i.e. subfamily Monotropaodieae should be treated as a separate family, Monotropaceae.