[Wikipedia] Europe, North Africa, and the Middle East native: Mentha pulegium, commonly (European) pennyroyal, or pennyrile, also called mosquito plant[1] and pudding grass,[2] is a species of flowering plant in the mint family, Lamiaceae, native to Europe, North Africa, and the Middle East (link added by Mary Ann Machi)

[Wikipedia] Invasiveness: In California, where it is considered an invasive species, it occupies a similar niche, in seeps, streamsides, vernal pools and swales, marshes, and ditches. There is some speculation that it may displace native species in these areas. (link added by Mary Ann Machi)