As of May 2014, 30 species are accepted by authorities at Kew Royal Botanic Gardens: Included in the list below are names accepted in previous versions but now regarded as synonyms.

Echinodorus angustifolius Rataj - syn of Helanthium bolivianum (Rusby) Lehtonen & Myllys
Echinodorus argentinensis Rataj - syn of Echinodorus grandiflorus (Cham. &
Schltdl.)
Micheli
Echinodorus aschersonianus Graebn. -
syn of Echinodorus uruguayensis Arechav
Echinodorus berteroi (Spreng.)
Fassett - from South Dakota to Argentina
Echinodorus bleherae or E. bleheri Rataj - syn of Echinodorus grisebachii Small
Echinodorus bracteatus Micheli - from Nicaragua to Ecuador
Echinodorus cordifolius (L.) Griseb. -
from Illinois to Paraguay
Echinodorus cylindricus Rataj - Brazil
Echinodorus decumbens Kasselm. -
Brazil
Echinodorus densinervis Somogyi - Brazil
Echinodorus eglandulosus Rataj - Brazil
Echinodorus emersus Lehtonen - Ecuador, Peru, Bolivia
Echinodorus floribundus (Seub.)
Seub. -
Veracruz to Argentina
Echinodorus gabrielii Rataj - Brazil
Echinodorus glaucus Rataj - Brazil, Bolivia
Echinodorus grandiflorus (Cham. &
Schltdl.)
Micheli  - Brazil, Paraguay, Uruguay, Argentina, Venezuela, Florida
Echinodorus grisebachii Small - from Nicaragua to Brazil
Echinodorus heikobleheri Rataj  - Brazil
Echinodorus horizontalis Rataj - from Guyana to Peru
Echinodorus inpai Rataj  - Brazil
Echinodorus isthmicus Fassett - syn of Helanthium bolivianum (Rusby) Lehtonen & Myllys
Echinodorus lanceolatus Rataj - Brazil
Echinodorus longipetalus Micheli - from Suriname to Argentina
Echinodorus longiscapus Arechav. -
Brazil, Argentina, Paraguay, Uruguay
Echinodorus macrocarpus Rataj - syn of Echinodorus pubescens (Mart.
ex Schult.f.)
Seub.
ex Warm. -
Brazil
Echinodorus macrophyllus (Kunth) Micheli  - Brazil, Bolivia
Echinodorus major (Micheli) Rataj - Brazil
Echinodorus nymphaeifolius (Griseb.)
Buchenau - syn of Albidella nymphaeifolia (Griseb.)
Pichon
Echinodorus opacus Rataj - syn of Echinodorus uruguayensis Arechav
Echinodorus osiris Rataj - syn of Echinodorus uruguayensis Arechav
Echinodorus ovalis C.Wright - syn of Echinodorus cordifolius (L.) Griseb
Echinodorus palaefolius (Nees & Mart.)
J.F.Macbr. -
Nayarit,  Minas Gerais
Echinodorus paniculatus Micheli in A.L.P.de Candolle & A.C.P.de Candolle - from Mexico to Argentina
Echinodorus reptilis Lehtonen - Brazil, Argentina, Paraguay
Echinodorus scaber Rataj - from Nicaragua to Paraguay
Echinodorus subalatus (Mart.
ex Schult.f.)
Griseb. -
from Mexico to Paraguay; also Cuba
Echinodorus tenellus  (Mart.
ex Schult.f.)
Buchenau - syn of Helanthium tenellum (Mart.
ex Schult.f.)
J.G.Sm.
in N.L.Britton
Echinodorus trialatus Fassett - Panama, Colombia, Venezuela, Brazil
Echinodorus tunicatus Small - from Costa Rica to Bolivia
Echinodorus uruguayensis Arechav. -
Chile, Argentina, Paraguay, Uruguay, Brazil
Echinodorus virgatus  (Hook. &
Arn.)
Micheli - syn of Echinodorus palifolius (Nees & Mart.)
J.F.Macbr
As of May 2014, 30 species are accepted by authorities at Kew Royal Botanic Gardens: Included in the list below are names accepted in previous versions but now regarded as synonyms.
Echinodorus angustifolius Rataj - syn of Helanthium bolivianum (Rusby) Lehtonen & Myllys
Echinodorus argentinensis Rataj - syn of Echinodorus grandiflorus (Cham. & Schltdl.) Micheli
Echinodorus aschersonianus Graebn. - syn of Echinodorus uruguayensis Arechav
Echinodorus berteroi (Spreng.) Fassett - from South Dakota to Argentina
Echinodorus bleherae or E. bleheri Rataj - syn of Echinodorus grisebachii Small
Echinodorus bracteatus Micheli - from Nicaragua to Ecuador
Echinodorus cordifolius (L.) Griseb. - from Illinois to Paraguay
Echinodorus cylindricus Rataj - Brazil
Echinodorus decumbens Kasselm. - Brazil
Echinodorus densinervis Somogyi - Brazil
Echinodorus eglandulosus Rataj - Brazil
Echinodorus emersus Lehtonen - Ecuador, Peru, Bolivia
Echinodorus floribundus (Seub.) Seub. - Veracruz to Argentina
Echinodorus gabrielii Rataj - Brazil
Echinodorus glaucus Rataj - Brazil, Bolivia
Echinodorus grandiflorus (Cham. & Schltdl.) Micheli  - Brazil, Paraguay, Uruguay, Argentina, Venezuela, Florida
Echinodorus grisebachii Small - from Nicaragua to Brazil
Echinodorus heikobleheri Rataj  - Brazil
Echinodorus horizontalis Rataj - from Guyana to Peru
Echinodorus inpai Rataj  - Brazil
Echinodorus isthmicus Fassett - syn of Helanthium bolivianum (Rusby) Lehtonen & Myllys
Echinodorus lanceolatus Rataj - Brazil
Echinodorus longipetalus Micheli - from Suriname to Argentina
Echinodorus longiscapus Arechav. - Brazil, Argentina, Paraguay, Uruguay
Echinodorus macrocarpus Rataj - syn of Echinodorus pubescens (Mart. ex Schult.f.) Seub. ex Warm. - Brazil
Echinodorus macrophyllus (Kunth) Micheli  - Brazil, Bolivia
Echinodorus major (Micheli) Rataj - Brazil
Echinodorus nymphaeifolius (Griseb.) Buchenau - syn of Albidella nymphaeifolia (Griseb.) Pichon
Echinodorus opacus Rataj - syn of Echinodorus uruguayensis Arechav
Echinodorus osiris Rataj - syn of Echinodorus uruguayensis Arechav
Echinodorus ovalis C.Wright - syn of Echinodorus cordifolius (L.) Griseb
Echinodorus palaefolius (Nees & Mart.) J.F.Macbr. - Nayarit,  Minas Gerais
Echinodorus paniculatus Micheli in A.L.P.de Candolle & A.C.P.de Candolle - from Mexico to Argentina
Echinodorus reptilis Lehtonen - Brazil, Argentina, Paraguay
Echinodorus scaber Rataj - from Nicaragua to Paraguay
Echinodorus subalatus (Mart. ex Schult.f.) Griseb. - from Mexico to Paraguay; also Cuba
Echinodorus tenellus  (Mart. ex Schult.f.) Buchenau - syn of Helanthium tenellum (Mart. ex Schult.f.) J.G.Sm. in N.L.Britton
Echinodorus trialatus Fassett - Panama, Colombia, Venezuela, Brazil
Echinodorus tunicatus Small - from Costa Rica to Bolivia
Echinodorus uruguayensis Arechav. - Chile, Argentina, Paraguay, Uruguay, Brazil
Echinodorus virgatus  (Hook. & Arn.) Micheli - syn of Echinodorus palifolius (Nees & Mart.) J.F.Macbr
Echinodorus