and general hardiness. A submerged culture system was developed for rapid micropropagation of this commercially important aquarium plant, ‘Amazon sword’ (Echinodorus ‘Indian Red’). Taxonomy The genus Baldellia seems to be very closely related. In the latest revision by Karel Rataj, 62 species, 2 subspecies, and 2 varieties are listed. All species of Echinodorus are variable according to hether they are growing emerse or submerged and their growing conditions. In addition they can hybridise in the wild or through artificial means. Many forms have been given subspecific status or as named forms in the aquarium trade. Accoording to aquarists some of these forms persist in all growing conditions. Species 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