Herb Robert is a member of the Geranium Family
(Geraniaceae) and is normally found in rocky woods and ravines. The flowers are about 1/2 inch across with 5 petals. The plant is about 1-2 feet tall and blooms from May to October. Herb Robert is found from Canada south to Maryland and west to Illinois.
It is believed that the plant is named for St Robert of Molesme, who's festival day falls about the time this flower begins to bloom in late April. It is also speculated that it was named for Robert Goodfellow, aka Robin Hood.