Much confusion exists in the identification of Mentha species because floras frequently apply the wrong names to species descriptions, and also because hybrids are common. Many species of Mentha have two types of plants: ones with small flowers that have only female parts, and ones with the usual, larger bisexual flowers. The bisexual flowers have exserted stamens. References: Harley (1972), Tucker and Naczi (2007).
This Genus’s Species in New England:
Visit this genus in the Dichotomous Key