薹草属Carex（莎草科Cyperaceae）是被子植物的大属，其分类历来被视为是一大难题。近来薹草属的系统分类学研究取得了较大进展，但在种的划分、属内组的界定等方面仍存在问题和严重分歧，反映出以往对薹草属研究方法单一，对多学科综合评价和分析系统分类问题的认识不足。.本研究旨在前人研究的基础上，坚持以居群概念为指导，对东亚-北美间断分布的稀花薹草组Carex sect. Paniceae植物进行深入的野外调查和标本采集，国内外主要标本馆标本的全面查阅和观测，用统计学方法分析种间及种内居群间的形态变异，探讨和评价形态性状（包括宏观形态、叶表皮、果囊及小坚果的微形态）的变异式样及其系统分类学意义，对疑难种开展DNA barcoding研究，结合分子系统学研究结果，对本组进行界定及全面的世界性修订。本项目既可以为Carex系统分类研究提供借鉴，也可以培养植物经典分类和系统进化研究的后备人才。

Cyperaceae, a monocot family in the order Poales, contains 106 genera and ca. 5400 species worldwide, with closest relatives, Juncaceae and Thurniaceae. With more than 2000 species, Carex L. is the largest genus in the family Cyperaceae. The genus has traditionally been divided into four subgenera: subg. Vigneastra (Tuck.) Kük., subg. Vignea (B. Beauv. ex Lestib.) Peterm., subg. Psyllophora (Degl.) Peterm., and subg. Carex. More recently, these subgenera are known to be largely polyphyletic or paraphyletic, with the notable exception of subg. Vignea. The genus Carex itself, however, is cosmopolitan and easily distinguished from the other genera of Cyperaceae based on the combination of unisexual flowers and achenes enveloped in perigynia..With a number of species and a large dispersal region, and limited specimens, the taxonomic revision and floristic studies on Carex are considered as one of the difficult problems in angiosperm. During the preparation of the regional florae, the investigation and taxonomy of Carex were fairly in-depth in the recent 40 years, but a lot of divergences and problems in species delimitation, generic subdivision, and geographical distribution etc. still need to be solved. All these indicate that the cognition of morphological characters and its systematic significance are far from a satisfactory status..Based upon field work, population sampling, specimen examination of the main herbaria both at home and abroad, this project will use statistical analysis and analyze the variation of the morphological characters, which are used to identify the species in Carex sect. Panicaeae. We will also evaluate the taxonomic significance/value of these characters, carry out phylogenetic analysis and DNA barcoding on Carex jackiana Complex and C. filipes Complex, and make a full-scale revision of Carex sect. Paniceae, as well as delimitate this section and similar ones. It can accelerate the taxonomic revision, systematics, origin, dispersal and the floristic studies of the whole genus Carex. The project will benefit for cultivating reserve talents of phytotaxonomy.