Oldenlandia corymbosa, commonly known as flat-top mille graines or diamond flower, is a species of plant in the family Rubiaceae. It is a commonly used herb in China and India for treating sore eyes, anthelmintic, antirheumatic, depurative, digestive, diuretic, pectoral, fever, jaundice, child birth, and stomachic medicine, while the roots are reported to have vermifuge properties.