West Highland Flora

Reddish Pondweed


Potamogeton alpinus

 

Potamogeton alpinus

Photo Carl Farmer
6 Aug 2003 Dunvegan, Skye

Occasional in lochs

Submerged leaves c 7-18 cm long.

ID: Has submerged leaves (shown in these pictures), and may also have floating leaves but these may be absent (no pictures of these yet).  Note that submerged leaves could be floating or floating leaves submerged depending on water level.  ID that follows relates to the submerged type of leaf.  These are more than 5 times as long as wide, without a point at the tip, mostly unstalked but not at all clasping the stem, and have 4-8 lengthwise veins on either side of the midrib, prominent ones more or less alternating with faint ones, unlike in P Gramineus where no faint one is nearer to the midrib than a prominent one.  Together with a round, not flattened or grooved, stem, this should identify the plant.

Other features: Floating leaves when present are about 4 times as long as broad and have stalks shorter than their blades.  Stipules are not stiff, about half as long as the leaves, appressed to the stem, often falling off as leaves mature.

The fruits are densely arranged on a typical pondweed spike (see e.g. Bog Pondweed).  Unlike on some pondweeds, the stalk is not thickened upwards towards the base of the spike.

 

Potamogeton alpinus

Photo Carl Farmer
6 Aug 2003 Dunvegan, Skye

 

Potamogeton alpinus

Photo Carl Farmer
6 Aug 2003 Dunvegan, Skye

 

Potamogeton alpinus

Photo Carl Farmer
6 Aug 2003 Dunvegan, Skye

 

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