Classification of Kobresia fragilis C. B. Clarke (Cyperaceae) and related taxa
囊状嵩草(莎草科)及相关类群的分类

The classification of Kobresia fragilis C. B. Clarke and related taxa were studied based on gross morphology and nutlet epidermal micromorphology. About 13 names have been involved in the species group. They could not be clearly defined using the morphological characters employed by previous authors. Thus, more than 200 sheets of 89 specimens of related taxa were studied thorough- ly, and the taxonomic significance of morpbological characters was re-evaluated. In order to further understand the classification of K. fragilis and its allies, micromorphology of nutlet epidermis of these taxa was observed under scanning electron microscope. Based on the results, K. curvata C. B. Clarke and K. fragilis were recognized. Other names were treated as synonymies of K. fragi- lis. K. clarkeana (Kükenthal) Kükenthal, K. clarkeana var. megalantha Kükenthal and K. curticeps (C. B. Clarke) Kükenthal var. gyirongensis Y. C. Yang were reduced to new synony- mies of K. fragilis. K. curvata was distinct from K. fragilis on both morphological and micromor- phological basis. One specimen of K. fragilis collected from Luqu, Gansu, China, represents anew distribution record of this species in Gansu.