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Potamogeton natans

Potamogeton natans
PotamogetonNatans.jpg
Scientific classification
Kingdom: Plantae
Clade: Angiosperms
Clade: Monocots
Order: Alismatales
Family: Potamogetonaceae
Genus: Potamogeton
Species: P. natans
Binomial name
Potamogeton natans
L.

Potamogeton natans (broad-leaved pondweed,floating pondweed,floating-leaf pondweed) is an aquatic species in the genus Potamogeton native to quiet or slow-flowing freshwater habitats throughout the Holarctic Kingdom.

It produces both floating and submersed leaves on the same plant. The floating leaves are ovate to oblong-ovate and almost always cordate 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 stipules are 4 to 17 cm long.

The submerged grass-like structures are called phyllodes, 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.


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Wikipedia

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