Mentha deleoi is described from Isola Grande, an islet in the Stagnone of Marsala (Trapani, NW Sicily), included within the homonymous Regional Oriented Nature Reserve. It is a perennial herb with an ephemeral annual cycle; in several morphological characters, it shows affinity with M. pulegium, a Eurimediterranean hemicryptophyte widely distributed in Sicily from coastal areas to high mountain habitats. Diagnostic and differential characters are provided, together with analyses of the biology, ecology, and chemistry of this new Sicilian endemic species. Owing to its extremely restricted distribution, small population size, and the potential impacts affecting the islet and its fragile habitat, resulting from centuries saliculture, a conservation plan is proposed, aimed at both in situ and ex situ protection.
Francesco Maria Raimondo (Wed,) studied this question.