In 1848, the German botanist Christain Ferdinand Hochstetter thought that C. Linné’s Elymus L. was too complex. He separated Elymus arenarius L., which has apparently different morphological characteristics, and used this species as the type to establish the genus Leymus Hochst. published in Flora (vol. 31, page 118). Despite the passage of 101 years, no one has paid attention to C. F. Hochstetter’s opinion. Until 1949, the German botanist Robert Kunds Friedrich Pilger published his book “The Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie” in 74 volumes published in “Additamenta agrostologica,” only to reaffirm the independent legal status of the genus Leymus. Robert Kunds Friedrich Pilger published his nine new combinations of Leymus since 1945 in this article. Although in 1938, the Japanese botanist Hiroshi Hara correctly combined the Elymus mollis Trinius into Leymu mollis (Trin.) Hara, he ended up as a combination of Elymus mollis Trin.—“Leymus mollis (Trin.) Hara, mss.” published in the 52nd volume of The Botanical Magazine (Japanese journal), entitled “Preliminary report of the Hidaka, Hokkaido (Yezo) XXVII.” Consequently, this correct combination by Hiroshi Hara was subsequently rejected by him and reduced to synonymy.