Callitriche stagnalis

Aquatic or mud-terrestrial, spreading or mat-forming, relatively robust with stems to c. 90 cm long, glabrous. Leaves variable, linear-spathulate to suborbicular, 2–25 mm long, 1–6 mm wide, 3–7-veined, petiolate; upper leaves rosetted. Flowers usually paired, a male and female together in 1 or both axils; bracteoles falcate, c. 1.5 mm long, membranous, persistent; stamen 1.4–4(–7) mm long, c. twice as long as fruit; styles erect, 2.5–4 mm long, becoming recurved in fruit, persistent. Fruit more or less circular, 1.2–1.7 mm long and wide, usually slightly longer than wide, subsessile, pale buff; wing prominent. Flowers and fruits mainly Sep.–Apr.