Home / Anomalous_Items / Aquatic_Macrophytes / Submerged_Leaves / Najas


Click on images for larger format

Name derivation:

Najas - Greek, a river nymph, naias.

Common names ‘brittle water-nymph’, ‘eutrophic water-nymph’, ‘Holly-leaved Naiad’.


Najas Linneaus  1753;  at least 37 species descriptions are currently accepted taxonomically.

Order Alismatales;  Family Hydrocharitaceae, or Najadaceae (until 1997).



Thin stems up to 1 mm in diameter.  Sheathed leaves are oppositely arranged and have serrulate martings, 7-15 teeth on each side, and 0.5-3.5 cm long.

Dioecious (N. marina), incomplete flowers 1-2 flowers per axil, up to 4  mm long with prominence of females in the U.K.(10x more than males)(Handley and Davy 2000). 


Similar genera:



Freshwater, to depths of 4-5 m. 

N. minor is native to Africa, Japan, India and central Europe, and intentionally introduced to Cayuga Lake, NYS USA in 1935.  It’s now invasive in New England USA.  [online].



Handley, R.J., and A.J. Davy  2000.  Discovery of male plants of Najas marina L. (Hydrocharitaceae) in Britain.  Watsonia 23:331-334.