“…Mentha longifolia, the other putative parent, has a somatic chromosome number of 2n = 24 in Europe, Asia, and Africa: Armenia (Makarov & Reznikova, 1972), Turkey (Harley & Brighton, 1977), and the former Yugoslavia (Harley & Brighton, 1977). Both the morphology and chemistry, however, vary widely, and at least 20 essential oil chemotypes can be identified (we have omitted populations with 2n = 48 and 2n = 36, which we interpret as M. spicata or M. ×villoso-nervata Opiz): (1) cis-and trans-piperitone oxide; (2) cis-and trans-piperitone oxide and piperitenone oxide; (3) piperitenone oxide; (4) piperitone and limonene; (5) piperitone and carvone; (6) menthone and piperitone; (7) menthone and menthol; (8) menthone; (9) menthyl acetate, menthol, and menthone; (10) menthol; (11) (Shimizu & Ikeda, 1961;Baquar & Reese, 1965;Sticher & Flück, 1968;Hendriks & van Os 1972;Lawrence & Morton, 1974;Bayraktar-Alpmen, 1975;Kartnig & Still, 1975;Karasawa & Shimizu, 1978;Lawrence, , 1981bLawrence, , 1982aBanthorpe & al., 1979Banthorpe & al., , 1980Bellomaria & Valenti, 1979;Kapil & Sinha, 1979;Kuwahara & al., 1979;Kokkini-Gouzkouni, 1983;Bellakhdar & al., 1985;Vidal & al., 1985;Kokkini & Papageorgiou, 1988;Maffei, 1988;Shikimaka & Vorob'eva, 1988;Souleles & Argyriadou, 1988;Melkani & al., 1990;Fleisher & Fleisher, 1991Karasawa & al., 1995;Kokkini et al, 1995;Venskutonis, 1996;Baser & al., 1997;…”