Abstract: representative species selected from the different sections and series of Roegneria are examined in leaf epidermal anatomy in the present paper. Based on the leaf epidermal characters displayed by these species (including Roegneria species anatomized in the past), the rationalities of the dividing and coexisting Roegneria in the tribe Triticeae and the subdivision below the genus are confirmed, the evolutional levels and systematic relationships of the major taxa in the genus also revealed. In these characters, the forms of long cell walls, the guantity and shapes of short cells, the types and density of appendages, and so on possess probably the values for differentiating sections or series; the winding of long cell walls, the increase and crescent change of short cells, the decrease of prickle hairs, the emergence of hooks and macro 1hairs, and so foth are probably parallel to the phylogenetic development of the taxa. The last results show that the sect. Goulardia (Husnot) L. B. Cai is the most primitive in Roegneria; in the phylogenetic process, it might produce the sect. Roegneria and the sect. Ciliaria (Nevski) H. L. Yang which are more advanced than it, and also the sect. Curvata (Nevski) H. L. Yang which is the most advanced among the 4 sections. In the sect. Ciliaria (Nevski) H. L. Yang, the ser. Dentatae Nevski is the most primitive in the section, the ser. Ciliares Nevski is more advanced than the former, the ser. Platyphyllae L. B. Cai is the most advanced among the 3 series, and the ser. Ciliares Nevski and the ser. platyphyllae L. B. Cai might be derived successively from the ser. Dentatae Nevski. Furthermore, the systematic relationships of Roegneria basically are in agreement with the evidences furnished by sytology and morphology.

Key words: Roegneria, Leaf epidermis, Taxonomic significance