Glabrous, sometimes hairy perennial; stems many, to 80 cm, erect or ascending with long, sparingly leafy branches. Leaves 2-4 mm wide, lanceolate or 3-veined; middle and upper leaves alternate. 1-veined. Sepals 3 mm, ovate, acute, inconspicuously ciliate. Petals 11-15 mm yellow. Stigmas clavate. Capsule 2-3 mm, wider than long, subglobose; beak minute or absent. Fl. 7. Reedbeds and muddy places. 10 m.
Mediterranean Region; Portugal.