The new speciesPsathyrostachys stoloniformisnative to China is described. The karyotype was investigated by C‐, N‐, and Ag‐banding. The new species has 2n = 2x = 14, including 8 metacentric and 6 SAT‐chromosomes with minute satellites, distributed either on 3 or on 4 chromosome pairs. The C‐banding pattern comprises from one to six conspicuous and from zero to three very small bands per chromosome. Often two bands placed close together appear as one large band. The karyotype suggests thatP. stoloniformisis closely related toP. juncea.N‐banding produced very weak or no bands. Meiotic analyses of interspecific hybrids revealed a high chiasma frequency indicating thatP. stoloniformishas the same basic genome (N) asP. huashanica, and