Monoclinous. Annual or perennial, emersed. Leaves erect, with pellucid markings as dots or lines or not; emersed leaves petiolate, blade linear to broadly ovate, margins entire or undulate, apex acute to acuminate, base truncate to cordate; submersed leaves mostly sessile phyllodes, margins entire or undulate, apex acute to acuminate. Inflorescence erect, emersed, racemose or paniculate, rarely umbelliform. Flowers perfect; pedicels often elongating after an thesis; sepals reflexed to spreading; petals white, larger than sepals; stamens 9- many; carpels many, achenes terete, often longitudinally costate and glandular.