BOG PONDWEED

Potamogeton polygonifolius

Pondweed Family [Potamogetonaceae]

month8may month8jun month8june month8jul month8july month8aug month8sep month8sept

status
statusZnative
flower
flower8green
inner
inner8cream
morph
morph8actino
petals
petalsZ4
type
typeZspiked
type
typeZbell
stem
stem8round

13th July 2012, slopes of High Tove, Watendlath, Cumbria. Photo: © RWD
A deep water-filled hole disguised with floating Bog Pondweed that your Author nearly walked straight into. Occupies shallow water in boggy areas of acidic places such as Western hills.


13th July 2012, slopes of High Tove, Watendlath, Cumbria. Photo: © RWD
Has floating broad oval leaves.


13th July 2012, slopes of High Tove, Watendlath, Cumbria. Photo: © RWD
And compact flowering spikes reminiscent of those of the Plantain Family, especially those of Greater Plantain (but that is not an aquatic plant).


13th July 2012, slopes of High Tove, Watendlath, Cumbria. Photo: © RWD
The floating leaves obscure many submerged narrower leaves (not shown!) peeling off a stalk at intervals.


13th July 2012, slopes of High Tove, Watendlath, Cumbria. Photo: © RWD
The flowering stalk is like a green sparkler firework, but much shorter. The flowers are at first compacted (centre right) before opeing up (top right).


13th July 2012, slopes of High Tove, Watendlath, Cumbria. Photo: © RWD
Flowers opened up showing four green 'petals' or sepals, and four cream-coloured anthers? within.


13th July 2012, slopes of High Tove, Watendlath, Cumbria. Photo: © RWD


13th July 2012, slopes of High Tove, Watendlath, Cumbria. Photo: © RWD
Flowers in close-up.


13th July 2012, slopes of High Tove, Watendlath, Cumbria. Photo: © RWD
Flowering stalks that are going to fruit lie on the surface of the water.


13th July 2012, slopes of High Tove, Watendlath, Cumbria. Photo: © RWD
Two new flowering stalks just emerging from the water (top right)


13th July 2012, slopes of High Tove, Watendlath, Cumbria. Photo: © RWD
Flowers gone to fruit. New flowering spike just emerging from below the surface (bottom right).


13th July 2012, slopes of High Tove, Watendlath, Cumbria. Photo: © RWD
Leaves broad oval to broad laneolate, green tending to reddish.


13th July 2012, slopes of High Tove, Watendlath, Cumbria. Photo: © RWD
Leaves have many feint dark veins and a glossy finish.


Hybridises with :

  • Broad-leaved Pondweed (Potomogeton natans) to produce Potomogeton × gessnacensis occurs only in 2 hectads in West Wales.
  • Various-leaved Pondweed (Potomogeton gramineus) to produce Potomogeton × lanceolatifolius but not seen since 1999.
Since the above photos were taken in Cumbria, it can be safely assumed that it is not any of the sbove hybrids, but both Broad-leaved Pondweed and Various-leaved Pondweed grow extensively in Cumbria.

Easily mistaken for :

  • Various-leaved Pondweed (Potomogeton gramineus) which very variable leaves but also has stipules which Bog Pondweed lacks.
  • Loddon Pondweed (Potomogeton nodosus) which is quite rare, has flower stalks which thicken at the top and occurs near Bristol.
  • American Pondweed (Potomogeton epihydrus) which is fairly rare, has narrow oval leaves and occurs in mid Lancashire and Outer Hebridean lochs.
  • Fen Pondweed (Potomogeton coloratus) which is fairly rare, which also has reddish but narrow oval leaves but they are translucent and occurs mainly in the Fens.
All the above have broadly similar floating leaves. Many of the above Pondweeds hybridise with ome another or with other Pondweeds, see the full Potomogeton Hybrid Chart

Slight resemblance to : Greater Plantain (the flowering spikes only), but that doesn't grown in water.

Grows in shallow (fresh?) water on acidic lands, such as damp mountain sides and valleys, in flushes and bogs or, sometimes occasionally in on dried out mud. Bog Pondweed is by far the commonest pondweed to grow in acidic places.


  Potamogeton polygonifolius  ⇐ Global Aspect ⇒ Potamogetonaceae  

Distribution
 family8Pondweed family8Potamogetonaceae

 BSBI maps
genus8Potamogeton
Potamogeton
(Pondweeds)

BOG PONDWEED

Potamogeton polygonifolius

Pondweed Family [Potamogetonaceae]