凤丫蕨属（Coniogramme Fée）隶属广义凤尾蕨科的珠蕨亚科，中国西南地区为其分布中心。由于形态性状复杂且易受生境影响发生较大变异，凤丫蕨属的分类十分混乱，且各类群间的系统关系不清，是蕨类植物中分类非常困难的类群之一。本项目拟在标本考证和大量野外考察的基础上，全面掌握物种形态性状的变异规律，探索稳定的分类特征，结合细胞学等方面的研究，解决凤丫蕨属的物种划分问题。同时，选择叶绿体基因组的8个DNA区段序列和2个核基因序列为分子标记，用最大简约法、最大似然法和贝叶斯分析构建凤丫蕨属系统发育树。在此基础上，探讨它们的起源时间、祖先分布区和地理散布式样。本项目的实施对于揭示凤丫蕨属各类群间的系统发育关系具有重要意义，为建立该属更趋自然的分类系统，完成世界性分类修订奠定基础。此外，还能为凤丫蕨属的合理开发及种质资源保护等提供重要的科学依据。

Coniogramme Fée, a genus of subfamily Cryptogrammoideae in Pteridaceae, is mainly distributed in SW China. The complexity of morphological characters and their great variation driven by adaptation to habitats have made the genus becoming one of the most difficult fern groups with respect to its phylogeny and taxonomy. In this project, basing on specimen examination and a number of field work, we aim to get a comprehensive grasp of variation pattern of morphological characters and explore stable ones in taxonomy. Combined with cytology and other aspects of the research, the problem of species classification in Coniogramme will be resolved. At the same time, we will use DNA sequences derived from eight chloroplast regions and two nuclear genes as molecular markers, to construct the phylogenetic trees of all species of Coniogramme by different methods (Maximum parsimony, Maximum likelihood, and Bayesian inference). Based on the above researches, we will also explore their origin time, original location, and distribution pattern. This project will greatly contribute to solve their phylogenetic relationships. It will provide important scientific basis for the construction of a natural phylogenetic system and a worldwide taxonomic revision on this fern genus. Moreover, our study can also give directions for optimal use and conservation of plant resources of Coniogramme.