The Sutera palustris belongs to Scrophulariaceae (the Figwort family). It is a perennial herb that is distributed to South Africa. This herb grows in marshy places and can reach 30-60 cm in height. The stem is erect, closely branched, slender and rigid. The leaves are linear, opposite, glandular-puberulous, entire or slightly toothed. The flowers are pink with the eye yellow, and bloom in the terminal racemes. The fruits are capsule, about 2 mm long.