American Corn Mint, Corn Mint, Field Mint, Wild Mint: Mentha canadensis (Synonyms: Mentha arvensis,Mentha arvensis var. arvensis, Mentha arvensis var. canadensis, Mentha arvensis var. glabrata, Mentha arvensis var. lanata) - Inflorescence of axillary verticels subtended by large leaves, the internodes fairly wide.
Spearmint: Mentha spicata (Synonyms: Mentha cordifolia, Mentha longifolia, Mentha longifolia var. mollissima, Mentha longifolia var. undulata, Mentha spicata var. longifolia, Mentha spicata var. spicata, Mentha sylvestris, Mentha viridis) -
Peppermint: Mentha xpiperita ssp. citrata (Synonyms: Mentha aquatica x Mentha spicata, Mentha aquatica var. crispa, Mentha dumetorum, Mentha piperita) -