Callitriche palustris var. palustris

Amphibious. Leaves dimorphic; lower leaves linear, 5–20 mm long, 0.5–1 mm wide, 1-veined, emarginate; upper leaves elliptic to suborbicular, 5–15 mm long, 1–4 mm wide, sometimes lobed, 3–5-veined, petiolate, rosetted. Flowers usually paired in axils, male and female together; bracteoles narrow-ovate, 0.5–1 mm long, membranous, deciduous; stamen to c. 5 mm long, much longer than fruit; styles erect or slightly spreading, 1–2 mm long, deciduous. Fruit obovate, 0.8–1 mm long, 0.7–0.9 mm wide, subsessile, dark brown; wing broader at apex, tapering away at base. Flowers and fruits Nov.–Feb. (few records).