Myriophyllum heterophyllum

Morphological keys (such as Aiken, 1981) are available but rely mostly on characters of flowers and fruits, which may not be present, as M. heterophyllum rarely flowers. It can best be recognised by its dense underwater growth and undivided, serrate emergent leaves (Q-bank, 2015).
Genetic identifications using the nuclear ribosomal DNA internal transcribed spacer regions (ITS) have become common (Moody and Les, 2002;Thum et al., 2006).