Mentha canadensis

About

Mentha canadensis is a species of mint native to North America and the eastern part of Asia. In North America, it is commonly known as Canada mint, American wild mint, and in Asia as Chinese mint, Sakhalin mint, Japanese mint, and East Asian wild mint. The flowers are bluish or have a slight violet tint. The plant is upright, growing to about 30–60 cm (12–24 in) tall. The leaves are opposite, and flower clusters appear in the upper leaf axils. This mint grows in wet areas but not directly in water, so it will be found near marshes, and lake and river edges. Plants bloom from July to August in their native habitats.

Summary from Wikipedia