| Echinodorus ovalis C. Wright, 1871 |
| Echinodorus palifolius (Nees & Mart.) J.F. Macbr., 1931 |
| Echinodorus paniculatus Micheli, 1881 |
| Echinodorus paniculatus var. paniculatus Micheli, 1881 |
| Echinodorus parvulus Engelm., 1856 |
| Echinodorus pellucidus Rataj, 1975 |
| Echinodorus radicans (Nutt.) Engelm., 1848 |
| Echinodorus rostratus (Nutt.) Engelm., 1848 |
| Echinodorus schlueteri Rataj, 1981 |
| Echinodorus subalatus (Mart. ex Schult. f.) Griseb., 1866 |
| Echinodorus subalatus subsp. andrieuxii (Hook. & Arn.) R.R. Haynes & Holm-Niels., 1986 |
| Echinodorus tenellus (C. Mart.) Buchenau, 1868 |
| Echinodorus tenellus var. latifolius (Seub.) Fassett, 1955 |
| Echinodorus tenellus var. parvulus (Engelm.) Fassett, 1955 |
| Echinodorus virgatus (Hook. & Arn.) Micheli, 1881 |
| Helanthium (Benth. & Hook. f.) Engelm. ex J.G. Sm., 1905 |
| Helanthium bolivianum (Rusby) Lehtonen & Myllys, 2008 |
| Helanthium nymphaeifolium (Griseb.) Small, 1909 |
| Helanthium parvulum (Engelm.) Small, 1909 |
| Helanthium tenellum (Mart.) Britton, 1856 |