Leaf cross-section of Allium erimomeli (A–D) and A. occultum (E, F). A. Leaf semicylindrical outline with five abaxial ribs, and a flat to slightly concave adaxial surface. B. Higher magnification of the dotted rectangle in A, showing the epidermal cells and the two-layered palisade tissue with elongated cylindrical cells. C. Epidermis composed of small cells with wavy thickened walls (arrow), and a sunken stoma (circle). D. Vascular bundle. E. Subcylindrical to terete outline with six ribs. F. Epidermis composed of small cells with wavy thickened walls (arrow), and a sunken stoma (circle) and the vascular bundle (inset in F).