Najas L.
Leaves inconspicuously toothed, with auriculate sheaths, up to 5 cm long, 1–3 mm wide. Carpels with 2 or 3 stigmas
Leaf auricles obtuse up to 0.5 mm long. Seed less than 1.7 mm long. Monoecious annual or short-lived perennial. Port Jackson. Fl. spring-autumn Najas browniana
Leaf auricles acuminate, 0.5–1.5 mm long. Seed 1.7 mm or more long. Monoecious or dioecious annual or short-lived perennial. Coast. Fl. spring–autumn Najas tenuifolia