Pondweeds

[Johnny81]

The next excursion in my Botanical learnings is the confusing family of Pondweeds, here are three species I have managed to find this summer and have attempted an ID, but unsure. I can appreciate if a full ID is too difficult from photographs alone.
1.Broad-leaved Potamogeton natans?

2. Unsure, this may be a fallen waterside plant?

3.Bad pic but was submerged, couldn't fish it out and cropped it best I could. Thought Opposite-leaved Groenlandia densa but closer inspection could be Curled pondweed Potamogeton crispus.

Many thanks.

[Tiggrx]

1. yes Broad-leaved Pondweed
2. A species of Water-starwort (Callitriche)
3. Probably Perfoliate Pondweed (Potamogeton perfoliatus) - the alternate leaves rule out Opposite-leaved Pondweed

[Johnny81]

Thanks for the quick reply Tiggrx. The leaves on plant 3 did look opposite till I could zoom the picture in and I certainly ruled it out then. Interesting group these Pondweeds.

[Dorts]

Originally Posted by Johnny81

Interesting group these Pondweeds.

That's an understatement Johnny. There are nearly 20 species and two dozen known hybrids recorded in Britain, enough to keep you going for a lifetime!
Dorts.

[AlanS]

The Callitriche looks a lot like C. obtusangula to me. Tricky plants to be sure of, even with a specimen in hand, but the leaf-veining looks correct in the photograph, as is leaf-shape.

A rare plant up here with me (I believe I hold the record for northernmost discovery, when I found it in ditches on the margin of Loch Lomond many years ago). However, should be fairly frequent in lime-rich water in Northamptonshire, where I assume you found it.

Alan

[Johnny81]

Yes Alan was found in a tiny outlet (more like a ditch) of the river nene in Northampton, which runs off into a pipe of some sort, most of the other flora in this "ditch" is Water forget me not. (SP 74597 62807). I may try fish a little out and get some better photos at some point and put them on this thread.