1 Brief Taxonomic History of Carex Sect.Rhomboidales 1.1 Introduction 1.2 Brief taxonomic history of Carex sect.Rhomboidales before Kükenthal(1909) 1.3 Brief taxonomic history of Carex sect.Rhomboidales since Kükenthal(1909) 1.4 Commentary on the taxonomic systems of Carex sect.Rhomboidales 2 Achene Micromorphology and Its Systematic Implications Summary 2.1 Introduction 2.2 Materials and methods 2.3 Results 2.4 Discussion Appendix 2-1 3 Perigynium Micromorphology and Its Systematic Implications Summary 3.1 Introduction 3.2 Materials and methods 3.3 Results 3.4 Discussion Appendix 3-1 4 Leaf Anatomy and Its Taxonomic Implications Summary 4.1 Introduction 4.2 Materials and methods 4.3 Results 4.4 Discussion Appendix 4-1 5 Morphological Characters and Variations Summary 5.1 Habit 5.2 Rhizomes 5.3 Culms 5.4 Leaves 5.5 Involucral bracts 5.6 Inflorescence 5.7 Scales 5.8 Perigynia 5.9 Achenes 6 Taxonomic Treatment Summary 6.1 Materials and methods 6.2 Taxonomic synopsis 6.3 Descriptions of species References Index to Visited Herbaria or with Specimens on Loan Index to Scientific Names