Pennyroyal, Mentha pulegium, aggressive invader and a non-native mint
- a dicot in the Lamiaceae family -
Common names: squaw mint, tickweed, stinking balm, mosquito plant.

Denise showing the height of the mature minty herb.
Pennyroyal has light blue flower whorls along the main stem.
Denise Robertson, a Park Ranger at Lake Kaweah and a new trail guide for 2001, was kind enough to pose with this strongly scented herb to give us some dimension to the size of the mature plant. Thanks Denise. This pungent herb grows in the path near the number 12 marker on the Swamp Trail. Its groundcover-like growth habit changes dramatically in May, when the square bloom stalks appear, growing to 24". It also looses its reddish hue as the temperatures rise. Light blue to light lilac colored flowers form whorls along the main stem, very similar to horehound. The dried flower stalks often persist in the landscape through the winter.

Pennyroyal has a groundcover growth habit with a reddish hue to the leaves in wintertime.
Herbalist Eric Pollard said pennyroyal oil is a "highly toxic oil, used mostly as a pesticide." It can kill "if  less than a teaspoon is ingested." Pennyroyal is used as a household ant and flea repellent. 

Warning   causes internal bleeding and death if ingested as a tea or oil.

We will be attempting to eliminate this toxic non-native herb from the preserve.

back to plants          next plant F