maybe an echinodorus? can't seem to find one that matches.

hi, i thought these were really nice plants and they look great in the aquarium, but i am dying to know what they actually are.
i found them growing along the bank and in the water. on land they are small and have rounded leaves with a little point at the end. the stems are not very long. in the water they are long and look sort of like some species of crypt or swordplant. they vary a lot based on location and the amount of light they are receiving. some are very reddish and dense, others looked almost like vallis and had a much straighter edge. they also put out a third kind of leaf that sits at the surface in a lilly like fashion. it looks more like the emersed leaf than the aquatic one. the plants were growing in amongst massive floats of algae, fairly close to shore in a muddy substrate. the water itself was muddy and frequently disturbed. collected from the calero reservoir, santa clara, california.

this picture shows three diferent looking plants but i am pretty sure they are all the same species. they came from spots with varying levels of light exposure in the water.
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this one shows the terrestrial leaf growing in the middle of the plant. since moving them out of the lake and into my tank a few days ago, they have all grown a couple of these leaves, i think in response to being exposed to air for a few hours while being transported. when on land, the leaf has a stem that is only a few inches long. some of the plants in the lake had a few of these if they were close to the edge of the water.
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any thoughts?

Looks like a pondweed (Potamogeton sp.). There are several species with oval floating leaves like you describe. This page has range maps for US species so you can see which ones are in your state, to help narrow it down a bit.

Looks like a pondweed (Potamogeton sp.). There are several species with oval floating leaves like you describe. This page has range maps for US species so you can see which ones are in your state, to help narrow it down a bit.

ok, i've looked at a bunch of potamogeton pictures and i can't find one that quite matches.
the problem i'm running across is that all the potamogeton species seem to have leaves that come off a stem, whereas the plant i have grows leaves out from the base, like a swordplant.
thanks for trying, but i don't think thats quite right. i'll go get some pictures of the habitat and of the emersed plants and see if that helps. maybe i could look it up by it's terrestrial form more easily.

This site is helpful: http://aquat1.ifas.ufl.edu/node/34

It's for Florida aquatic plants, but it might at least get you close. I still think it's a Potamogeton; I've seen some with the rosette of submersed leaves and the floating elliptical leaves. Unfortunately I didn't take pictures.

I think your first hunch was correct; some kind of Echinodorus. Most likely an ornamental hybrid introduced by an aquarist, who's hoping to come back and harvest periodically.

Looks like a sword to me...

hey, it turns out it definitely is a sword of some kind, although my eye isn't good enough to positively identify it. the leaves have changed dramatically since i put it in my tank and it looks exactly like the swordplants being sold in pet stores, the ones that come in little tubes without any water. i really hope that with some time and extra light it will re-grow its pretty aquatic foliage. in the meantime, thanks for all your help.

I have found Echinodorus in the wild as well - it was very exciting. It is doing well in my pond.