Abstract: The biosystematic relationships among Roegneria kamoji Ohwi, R. ciliaris (Trin.) Nevski and R. japonensis (Honda) Keng in the tribe Triticeae Dumortier were studied in the present paper by the methods of morpho-logical comparison and karyotype analysis. Morphologically, R. kamoji was quite different from the other two species, i. e. R. ciliaris and R. japonensis. But there was very slight disparity between the latter two species. Therefore, the classification of the two species was very difficult. Cytologically, the karyotype formulae of the three species were as follows:R. kamoji, 2n = 6x = 42 = 30m+8sm +4SAT;R. ciliaris, 2n = 4x =28 = 18m + 6sm+ 4SAT; R. japonensis, 2n=4x=28 = 18m+6sm+4SAT. The karyotype of R. ciliaris and R. japonensis showed non-significant difference from the analysis of t-test, while the karyotype of R. kamoji was substantially different from those of the other two species. Based on above-mentioned results, the authors suggest R. ciliaris and R. japonensis be combined into one species.

Key words: Triticeae； Roegneria