Magnoliophyta

Ovules (and seeds) enclosed within carpels (fruits); the carpels bearing stigmas upon which the pollen lodges. Pollen produced in the anthers of stamens. Carpels and stamens usually surrounded by a perianth; the whole constituting a flower which may be uni- or bi-sexual (= angiosperms) Magnoliophyta
Flowers usually 3-merous. Leaf venation usually parallel. Embryo with 1 cotyledon Plants usually herbaceous rarely woody and then ± unbranched) Liliopsida
Ovary inferior
Partially or wholly submerged herbs, sometimes marine Hydrocharitaceae
Ovary superior; male flowers with 1 stamen Najas
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