Pat W. asked me to post the pics below for identification.

Thanks Charlie for posting these plants. It's the first plants in the pond and I would like to know what they are

Pat, I have a couple of patches of the same plant, but I haven't been able to properly identify it myself. I wouldn't rake it out or disturb it until a proper identification is found though. There's no way of knowing if it can spread through broken pieces, so I'd leave it alone.

I'll try to post some pics of mine today.

Thanks Al for the reply, hope a plant guy or gal comes along with answers

I am going to guess creeping water primrose.

http://aquaplant.tamu.edu/management-options/water-primrose/

Thanks Shorty- is that bad?

I have never had to deal with water primrose, it does spread but stays shallow.

Shorty, my primrose has a different leaf, but that was my first thought too. I was hoping for a flower of some kind, but none seen here yet. I still wouldn't be surprised if that's what it is.

If you google water primrose the shape of the leaf is sometimes round, sometimes pointed, it might be just how fresh or mature the growth is, a flower would definitely help nail the ID.

The stem is also green not that darker color

Pat,

Maybe I'm looking at these pics wrong but I see at least two species of plants. Is that correct?

Bill
They all the same plant

Just bumping this thread as I see Kelly Duffie is online and hope he sees it.

Thanks Bill

Pat,
I tend to agree with Shorty's call on this ID, although I'm actually not certain..
Primrose (Ludwigia spp), of which there are several species, generally have alternating leaves. Alligator weed; which is sometimes confused with primrose, has opposing leaves.
Your middle photo shows a portion of the submerged plant with opposing leaves, but it otherwise has characteristics of gator weed. A bloom would be most helpful!
Look at my embedded composite-photo and let me know if this plant has any resemblance to your plant (compare structural assembly and features rather than leaf-shapes). If so, please secure a better photo of your plant - say, a close-up of the last 6 to 8" of the stem with a coin included in the photo for size-reference.
I'd like to find out exactly what it is - for future reference.
KD

I'll remember that one Kelly, thanks.

Kelly Duffie for identification:

Seems to have opposing leaves

Check out the base of the leaf-stalk where it attaches to the stem. That little tell-tale nub next to the leaf-stalk is a clue - that points to Hygrophila. The opposing leaves further indicate Hygrophila; which is easily confused with some primrose species.
I'd suggest doing a web-search for Hygrophila polysperma and see if its descriptive characteristics match up to your plant.
If it is Hygrophila (which I rarely encounter in TX - so far), I would caution any inclinations to ignore its presence since it is an exotic species (a member of the Federal Noxious Weed List), and potentially invasive in suitable habitats.
Has anyone "dumped" any aquarium plants in your pond to your knowledge?

Kelly I was afraid that it might be that. A neighbors pond two downstream has that stuff also.. What should I do now?

There are several species of Hygrophila, some of which are native to the US. East India Hygrophila is the exotic species of greatest concern.
How extensive is its current population?
(Signing off for today. Tomorrow is a long day)

Strong work Kelly, that was a tough one.

hygrophila

Ugh now got to figure out what to do with it

Kelly
The stems don't appear to be squarish at all from what I can see....

There are maybe a dozen areas or less about 3' or so

What is the treatment options?

Pat - I passed through Palestine last week on a trip to meet up with Bob and his guys in N TX. I would've detoured through Oakwood to view this particular plant since it is quite new to me.
I sent your photos to Dr. Sink @ TAMU for further assessment. His response ("appears to be Hygrophila") mimics mine, but he suggested rolling the base of a stem between your fingers. The sensation of a "squarish stem" would likely confirm Hygrophila (i.e., the squared-stem might be felt, but not necessarily visible).
Considering that East India Hygrophila is an exotic species, it generally doesn't just "appear" somewhere without human-assistance. So, back to the previous question: To your knowledge, has anyone had the opportunity to release aquarium-plants into your pond? That action would pose the most likely route of introduction - IF it is indeed EIH.
Possibly jumping the gun on speculation since its ID hasn't been confirmed. Do the finger-roll suggestion and report back.

Kelly
I will roll some in the morning and get back to you. Would it be possible to bring some in for a positive id? Have weed will travel..

Roll some, in the morning??? Did this conversation take a tangent?

Actually, I'd like to get some samples of the plant - but certainly don't make such a drive for that purpose. I'll PM my address to you.
If you're able to collect two or three 12" terminal-stems of the stuff and put them in a zip-lock baggie (here we go again...) and mail them my way, I'd be much appreciative.
Place a moistened paper-towel in the zip-lock - and try to evacuate as much air from the bag as possible before sealing it. A padded envelope generally works best for mailing-purposes.
Option B is UPS, but may be more haSSle$.

We have a chamber vac and will evacuate a little air and seal it

Pat be careful, Might be some Narcs around here

Woodstock

According to TAMU there is only one treatment - Clipper. But, I'm speaking out of turn because it hasn't been 100% ID'd yet. Kelly knows more than I do!! If he says to use something else, I sure won't disagree.

We gonna pull some next Monday and send to Kelly for a positive id. Them we will know for sure

Pat - I thought I'd give you an update on your mystery plant...
I received your plant specimens in good condition and promptly took these PHOTOS.
Said photos were submitted to multiple aquatic specialists (PhDs) at major universities spanning from TX to FL.
So far, differing/conflicting opinions were received on the plant's ID; ranging from Ludwigia spp (one of the primrose species) to Hygrophila spp (some species are native, one is exotic).
Several key characteristics seem to have them puzzled (as was I); namely the variability of leaf-shapes, leaf arrangement on the stem, coloration patterns and the plant's mostly submerged growth-habit. Some of these traits point to Ludwigia, and some to Hygrophila. It might be possible that your plant is a hybrid of one or the other, and maybe an escapee of the aquarium industry.
I'm currently rehabbing some of your plant-samples to send to a contact at the U of FL Center for Aquatic and Invasive Plants for further assessment.
I'll make you aware of any further determinations as they become available.

Kelly,

I'm curious, can they do DNA testing on plants and is there a database to compare to?

Bill - a valid question, but I have no idea if a DNA database exists, or if "they" would go to such extremes unless the mystery-plant was posing "invasive" characteristics or problems.

Kelly thanks for looking into this "unique " plant for me. A neighbor a mile away has the same plant and it seems to grow in 3' or less water also . Maybe we will get lucky and it won't be so bad..... Here's hoping

Kelly, do the different species that were thought to be ID'd have different control options? Or will one control option be sufficient for all the suspected ID's?

Kelly here they are

Pat, your plant samples have been growing in a bucket on my patio all summer.
HERE are photos of your sample specimens taken when they first arrived.
The sample plants' growth-pattern "morphed" shortly after I began their rehab in a bucket (as shown HERE).
Oddly enough, the recuperating plants never returned to the growth-pattern displayed in the original photos.
I basically think it's one of the many species of primrose, but not one that I recall seeing before. As you'll note in the photos, there were some Lepidoptera worms that seemed to really enjoy munching on this plant.
Lastly, some bladderwort seeds evidently hitched a ride with your sample-submission.

Oh well that's not to bad .... Now I got blue green algae and not sure what if anything to do about it

Pat,
With all this rain over the last few weeks, have you seen a decrease in your BG algae?

Not that I can tell although that's what I was hoping for. It hasn't gotten any worse .
Also was hoping that the tilapias would change the situation