West Highland Flora

Long-stalked Pondweed


Potamogeton praelongus

 

Potamogeton praelongus

Photo Craig Robson
Jun-Jul 2004 Ardnamurchan

Occasional, in less acid lochs, usually in fairly deep water.  Search for washed-up bits.

Leaves c 5-15 cm long x 1.5-4 cm wide

ID: Leaves clasping the stem, but not completely surrounding it as is usual in P perfoliatus.  Stipules remain in place on mature stems and only fall when stem ageing, unlike those of P perfoliatus which disappear early.  Stipules up to 8 cm long on this species (up to 2 cm on P perfoliatus), opaque when dry (translucent when dry on P perfoliatus).  Leaf-tips clearly hooded, so that leaf-tip cannot be flattened without a tear or fold.

Other features: No specialised floating leaves.  Grows throughout the winter and can flower as early as May.  Infloresences on long stalks (8-20 cm), which may or may not be thickened towards the tip.

 

Potamogeton praelongus

Photo Craig Robson
Jun-Jul 2004 Ardnamurchan

 

Potamogeton praelongus

Photo Craig Robson
Jun-Jul 2004 Ardnamurchan

 

Potamogeton praelongus

Photo Craig Robson
Jun-Jul 2004 Ardnamurchan


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