Mentha longifolia (L.)Huds. - syn. Mentha sylvestris L. - Lamiaceae - horse mint, Rossminze
Herbaceous perennial plant, native to Europe, western and central Asia and northern and southern Africa, with a minty aroma.
„It has been widely confused with tomentose variant plants of Mentha spicata; it can be distinguished from these by the hairs being simple unbranched, in contrast to the branched hairs of M. spicata.“ http://en.wikipedia.org/wiki/Mentha_longifolia
„The effects of various methods of drying on the content and chemical quality of the essential oil of Mentha longifolia was studied. The most prominent component in both the air-dried and sun-dried leaf oils was menthone (47.9% and 38.3%, respectively), while oven-dried leaf oil had limonene as the major compound (40.8%), whereas pulegone was the major compound from the original fresh leaf oil. Menthone and pulegone were not detected in the oven-dried leaf oil. The essential oil underwent significant chemical transformation in its monoterpenoids when the leaves were dried by the three different methods. Due to the significant reduction of the potentially harmful pulegone and menthone by oven-drying, it is suggested that this herb should be oven-dried or cooked before consumption in order to reduce toxicity.“
[Effects of drying methods on the quality and quantity of the essential oil of Mentha longifolia L. subsp. Capensis. O.T. Asekuna, D.S. Griersonb, A.J. Afolayan. Food Chemistry, Volume 101, Issue 3, 2007, p.995–998]
Mentha longifolia as Mentha sylvestris L.
Dietrich, A.G., Flora regni borussici, vol.5 t.310 (1837)
Mentha longifolia; author: Rolf Marschner (2007), www.botanische-spaziergaenge.at