''Potamogeton natans'', commonly known as broad-leaved pondweed, floating pondweed, or floating-leaf pondweed, is an aquatic species in the genus ''

Potamogeton ''Potamogeton'' is a genus of aquatic, mostly freshwater, plants of the family Potamogetonaceae. Most are known by the common name pondweed, although many unrelated plants may be called pondweed, such as Canadian pondweed (''Elodea canadensis' ...

'' native to quiet or slow-flowing freshwater habitats throughout the Holarctic Kingdom.

Description

It produces both floating and submersed leaves on the same plant. The floating leaves are

ovate Ovate may refer to: * Ovate (egg-shaped) leaves, tepals, or other botanical parts *Ovate, a type of prehistoric stone hand axe * Ovates, one of three ranks of membership in the Welsh Gorsedd * Vates or ovate, a term for ancient Celtic bards ...

to oblong-ovate and almost always

cordate Cordate is an adjective meaning ' heart-shaped' and is most typically used for: * Cordate (leaf shape), in plants * Cordate axe, a prehistoric stone tool See also * Chordate A chordate ( ) is a bilaterian animal belonging to the phyl ...

at the base. They are dark green, leathery, opaque, with translucent longitudinal veins. They are 5 to 10 cm long, pointed at the tips, and rounded at the base. The

stipule In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole (botany), petiole). They are primarily found among dicots and rare among monocots. Stipules are considered part ...

s are 4 to 17 cm long. The submerged grass-like structures are called

phyllode Phyllodes are modified petiole (botany), petioles or leaf stems, which are leaf-like in appearance and function. In some plants, these become flattened and widened, while the leaf itself becomes reduced or vanishes altogether. Thus the phyllode co ...

s, are actually modified leaf stalks. The stems are cylindrical, without many branches, and grow from 1 to 2 metres. The main difference between this species and other pondweeds is a discoloured flexible joint just below the top of the long leaf stalk. The flower spikes are dense, and cylindrical. They are 5 to 10 cm long, pointed at the tip and rounded at the base. It flowers from May to September. The fruits are 4 to 5 mm long and

obovate The following terms are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade is divided into two or more leaflets) ...

References

External links

''Potamogeton natans''
in ''

Flora of North America The ''Flora of North America North of Mexico'' (usually referred to as ''FNA'') is a multivolume work describing the native plants and naturalized plants of North America, including the United States, Canada, St. Pierre and Miquelon, and Greenla ...

''
USDA PLANTS Profile
natans Freshwater plants Flora of Northern America Flora of temperate Asia Flora of tropical Asia Flora of Europe Plants described in 1753 Taxa named by Carl Linnaeus {{Alismatales-stub