The leaves of Mentha haplocalyx are long ovate to elliptic lanceolate, about 3-7 cm long, with sharp apex, broad cuneiform base, fine and sharp serrations on the edge, pubescence on the top, pubescence and glandular dots on the bottom.
Peppermint leaves are usually lanceolate, elliptic or oblong lanceolate, rarely oblong, similar in size to the former, apex is also sharp, base is wedge-shaped to nearly round, edge teeth serrate, hair on both sides, no glandular spots below
Water Mint cymes grow in leaf axils, bracts are linear lanceolate, campanulate calyx, 5-lobed, lobes are nearly triangular, corolla is light red or purple, sometimes also white.
Mint inflorescence and the former same, calyx for tubular bell, 5 calyx teeth, a narrow triangular drill, corolla for lavender.
