Callitriche wightiana Wallex Wight & Am.
Mostly perennial, glabrous, 40 cm or more long; stem branched; leaves 9-40 x 1-7 mm, submerged leaves sessile, floating leaves with short petiole, elliptic to spathulate or orbicular, entire, obtuse, attenuate at the base, upper most forming a rosette. Flowers, onto two per axil, but never of the same sex, sessile; male flower: bracts 2, c. 1.2 x c. 0.5 mm, stamen one, 0.5-2 mm long; female flower. bracts 2, oblong, obtuse, truncate, c. 2.5 x c. 1 mm, styles 2, filiform, c.1.2-3 mm long. Fruit schizocarp, mericaips winged from apex to base, sub-orbicular, c. 1-2 x 0.8 - 2 mm.
Fl. Per.: July-August
Type: Described from (Italy, Trieste) in fossis circa Tergestum aqua marinis pie-nun'.
Distribution: Europe, North and East Africa, Asia, Australia and New Zealand.
This species is not as common as Callitricbe palustris in our region, probably over looked.