Stuckenia

Stuckenia
Stuckenia pectinata
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Monocots
Order:	Alismatales
Family:	Potamogetonaceae
Genus:	Stuckenia Börner, 1912
Species
See text.

See text.

Stuckenia is a genus of flowering plants. It contains 32 species, subspecies, varieties, forms, and cultivars found in the nearly worldwide seas. Pondweed is a common name for plants in this genus.

These herbs present rhizomes but not turions; the tubers can be absent or present. The main difference between "Stuckenia" and "Potamogeton" is that the stipule joins the leaf base, when it is pulled the sheath and stipule comes away, similar to a grass sheath and ligule.

...
Wikipedia