Please Help ID Plants in Pond

[presto]

Hi Everyone,
My Father in Laws Pond is doing very well and there is a lot of wild plant growth that we would like to know the names of. In particular, the plants that are underwater in the picture unknownPlant1.

Any help with ID's is appreciated. I've attached the pictures below.

Thanks Again

[attachment deleted by admin]

[Anja]

Your unknown plant no.3 looks like rush: http://www.arthurleej.com/a-rush.html

Sorry, dunno about the other two.

[presto]

Thanks Anja,
It definitely looks like the same stuff.

Regards,
Chris

[Sue]

Maybe unknown plant2 is water plantain? They put up tiny white spray of flowers at some point in summer.

http://en.wikipedia.org/wiki/Alisma_plantago-aquatica

[presto]

Thanks Sue,
The leaves are definitely similar.
The plants are growing in the valley region so it looks like a good fit.

[presto]

Thanks everyone for helping out.
My Father in law is excited about the now known plants.
Were still very interested in the identity of the Unknownplant1 picture posted.

Anyone know where I could begin looking for the answer?
Books?
Websites?

Thanks