Mentha aquatica, L.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1972, Flora Europaea. Volume 3. Diapensiacea to Myoporaceae, Cambridge: Cambridge University Press : 185

9. M. aquatica L. , Sp. Pl. 576 (1753)

( M. hirsuta Hudson ).

Subglabrous to tomentose, often purplish perennial (10-)20- 90 cm, with strong scent. Leaves (15-)30-90 x (10-)15-40 mm, ovate to ovate-lanceolate, usually truncate at base, petiolate, serrate. Inflorescence of 2-3 congested verticillasters with inconspicuous bracts, forming a terminal head up to 2 cm in diameter, sometimes with 1-3 distant verticillasters below, in the axils of leaf-like bracts. Calyx (2-5-)3-4 mm, tubular, the veins distinct; teeth subulate or narrowly triangular. Pedicels hairy. Corolla lilac. Nutlets pale brown. 2n = 96. Europe except the extreme north. All except Rs (N) Sb but only as a naturalized alien in Is. Very variable in habit, leaf-shape and indumentum. Many infraspecific taxa have been recognized, at least some of which retain their characters in cultivation.