Najas

Najas, the water-nymphs or naiads, is a genus of aquatic plants. It is cosmopolitan in distribution, first described for modern science by Linnaeus in 1753. Until 1997, it was rarely placed in the Hydrocharitaceae, and was often taken as constituting (by itself) the family Najadaceae.
The APG II system, of 2003 (unchanged from the APG system, of 1998), places the genus in family Hydrocharitaceae, in the order Alismatales of the monocots.
An infrageneric classification of two sections is proposed: Section Americanae and sect. Caulinia.
Species
Najas affinis Rendle - South America, Senegal, Guinea-Bissau
Najas ancistrocarpa A.Braun ex Magnus - China, Japan, Taiwan
Najas arguta Kunth - Cuba, Costa Rica, Panama, South America
Najas australis Bory ex Rendle - India, Madagascar, Mauritius, KwaZulu-Natal, Seychelles
Najas baldwinii Horn - West Africa
Najas brevistyla Rendle - Assam
Najas browniana Rendle - southern China, India, Taiwan, Java, Cavern Island in Northern Territory of Australia
Najas chinensis N.Z.Wang - Primorye, China, Taiwan, Japan
Najas conferta (A.Braun) A.Braun - Cuba, Hispaniola, Panama, Brazil
Najas faveolata A. Br. ex Magnus
Najas filifolia R.R.Haynes - southeastern United States (Georgia, Alabama, Florida)
Najas flexilis (Willd.) Rostk. & W.L.E. Schmidt (1824) - temperate Northern Hemisphere
Najas gracillima (A.Braun ex Engelm.) Magnus - Asia, North America
Najas graminea Delile (1813) - Africa, Asia, New Guinea, Melanesia, northern Australia; naturalized in California and parts of Europe
Najas grossareolata L.Triest - Sri Lanka
Najas guadalupensis (Spreng.) Magnus - North and South America, Caribbean
Najas hagerupii Horn - Ghana, Mali
Najas halophila L.Triest - Java, New Guinea, Queensland
Najas heteromorpha Griff. ex Voigt - eastern India
Najas horrida A.Braun ex Magnus - Africa, Madagascar, Sinai
Najas indica (Willd.) Cham. (1829) - Indian Subcontinent, China, Southeast Asia, New Guinea
Najas kurziana Rendle - Bihar, East Timor
Najas madagascariensis Rendle - Madagascar; naturalized in Mauritius
Najas malesiana W.J.de Wilde - India, Bangladesh, Indochina, Malaysia, Indonesia, Philippines; naturalized in eastern Brazil
Najas marina L. (1753) - widespread and nearly cosmopolitan
Najas minor All. (1773) - widespread in Europe, Asia, Africa; naturalized in eastern North America
Najas oguraensis Miki - East Asia, Himalayas (Pakistan, Nepal, northern India)
Najas pectinata (Parl.) Magnus - Sahara
Najas pseudogracillima L.Triest - Hong Kong
Najas rigida Griff. - eastern India
Najas schweinfurthii Magnus - Senegal, Cameroon, Ethiopia, Sudan, Tanzania
Najas tenuicaulis Miki - Honshu Island in Japan
Najas tenuifolia R.Br. - Hong Kong, Southeast Asia, Australia
Najas tenuis Magnus – India, Sri Lanka, Myanmar
Najas tenuissima (A.Braun ex Magnus) Magnus - Finland, Russia, Hokkaido
Najas testui Rendle - western + central Africa
Najas welwitschii Rendle - tropical Africa, western India
Najas wrightiana A.Braun - Mexico, Central America, Cuba, Bahamas, Venezuela; naturalized in Florida
References
External links
Najadaceae in L. Watson and M.J. Dallwitz (1992 onwards) [http://delta-intkey.com/angio/ The families of flowering plants] : descriptions, illustrations, identification, information retrieval. Version: 9 March 2006. http://delta-intkey.com .
Najas japonica Nakai- Flavon's art gallery
Najadaceae of Mongolia in FloraGREIF
Aquatic plants
Hydrocharitaceae genera
Taxa named by Carl Linnaeus