Wolffiella denticulata (Hegelm.) Hegelm.

Perennial or perhaps sometimes annual. Fronds submerged, with the basal part near the surface of the water and the tip bent downwards, cohering 2-7 together (often star-like), ribbon-shaped, 2-7 mm long, 0.3-0.8 mm wide, with 2-4 marginal teeth. Inflorescence 1 on each frond. Flowers and fruits rare (flowering plants shorter and wider than vegetative ones). Seeds unknown. Not very gregarious, usually found mixed with other floating plants or between emergent reeds in pools and lakes.