131899 CURLED PONDWEED Potamogeton crispus (Potamogetonaceae) Aquatic. Freshwater perennial with 4-angled stems. Grows in still or slow-flowing water. FLOWERS are borne in small spikes (Jun-Sep). FRUITS have a long, curved beak. LEAVES are all submerged and alternate; they are translucent, up to 9cm long, narrowly oblong and blunt, with crinkly margins. STATUS-Widespread and common throughout.