Abstract: This paper gives a summary of the representative lycopsids of the Middle-Late Devonian, and investigates the variation and differentiation of their reproduction structures, root organs and anatomical characters. Concerning the taxonomic treatment, some of these lycopsids can be attributed to Lycopodiales, Protolepidodendrales and Isotales sensu lato, while the others cannot be classified into current system. Because of preservation factors and uniqueness of the characters, it is unclear that to what extent these taxa reflect a taxonomical diversity. These lycopsids demonstrate great complexities in reproduction structures, root organs and anatomy. These findings, on one side, broaden current knowledge about the early evolutionary history of the lycopsid characters, and on the other side, indicate that those satellite taxa should also be taken into consideration besides those whole or almost whole species when making a phylogenetic analysis.

Key words: Middle-Late Devonian, Lycopsid, diversity, cladistics

摘要： 对中晚泥盆世代表性的石松植物做了归类总结，并分析了其生殖结构、根器官和解 剖特征的分化。该时期的石松植物除了可归入石松目、原始鳞木目或广义水韭目的分子之外 ，还存在大量难以归入现有分类体系的分子。由于化石保存及性状的独特性，目前尚很难确 定这些属种究竟在多大程度上反映了分类学上的多样性。在性状层次上，无论是生殖结构、 根器官、还是解剖特征，中晚泥盆世的石松植物都体现了高度的复杂性。这些植物既拓宽了 对石松植物整个谱系的性状演化的认识，也暗示在进行谱系分析及分类时不仅要基于一些整 体植物种或者接近完整的属种，而且必须重视众多卫星分类单元的系统位置以及它们的演化 意义。

关键词: 中晚泥盆世, 石松植物, 多样性, 分支分析