Water clover (Marsilea quadrifolia). Found along the shores of Bantam Lake, Litchfield County, Conn., whence it has been introudced into various parts of the country, notably eastern Massachusetts. Native of Europe and Asia (After Britton & Brown)
Kohler's Medizinal-Pflanzen in naturgetreuen Abbildungen mit kurz erlauterndem Texte :.Gera-Untermhaus :Fr. Eugen Kohler,[1883-1914].biodiversitylibrary.org/page/303730