Spearmint is a glabrousto hairy perennial herbaceous plant extensively cultivated in North America, England, Germany and Holland. Spearmint is derived from a range of species, but the two most important sources worldwide are M. spicata and M. x gracilis. The other frequently cultivated varieties are M. trichoura Brig. and M. tenuis. The plant is from 25 to 75 cm (10 to 30 in.) high, with an erect, branched stalk exhibiting long, lanceolate leaves and flowers clustered in the form of spikes. The part used is the flowering tops. Spearmint has a warm, herbaceous, penetrating odor and a sharp, pungent flavor. Grade I peppermint must contain 1.0% essential oil (dried peppermint), while spearmint must contain 0.4% essential oil (dried mint) to meet International Standard requirements.
Leaves and flowering tops of spearmint contains essential oil (thymol), resin, gum, tannin.
