# Polygonum sp.



## davemonkey (Mar 29, 2008)

Can anyone id this smartweed? I found it in a waterway on dryland (but wet soil beneath). All growth is emerent, plants were about 1-4' tall in full bloom. (The water on the plants you see is because I put them in water to keep them turgid until I could get good photos...and get them to my tank to see if they survive in an aquarium. )

Note the two pistils per flower and 8 stamens. I was thinking _Polygonum pensylvanicum _(Pennsylvania smartweed, nearly as common as P. hydropiperoides in this area).









































































Thanks,
Dave


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## Cavan Allen (Jul 22, 2004)

I think you're probably right. There are no hairs at the top of the ocrea?


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## davemonkey (Mar 29, 2008)

Cavan Allen said:


> I think you're probably right. There are no hairs at the top of the ocrea?


Okay, I was not sure what that was called (which is why I took that last photo before zooming in to the blooms), so now I know. THANKS!! 

Right, there are no hairs on the ocrea, it is just smooth.

This is how I know I've chosen the right career path. I was sitting in my office bored to tears, so I got in the truck to look at some brush clearing and saw this plant flourishing where it was not expected to thrive. I pulled over and jumped out and , before I realized it, spent 2 hours cutting pieces, checking out the site, the soils, the slope of the waterway....trying to figure out how it was growing there. ...and it's all just part of my job...I get paid for this kind of stuff!

Anyhow, I'm still not sure how it will perform in an aquarium, but I brought some home to find out. I'll update if it starts growing submersed.

-Dave

EDIT: After doing some more reading, I don't expect it to do well completely sumberged. It is not as water-loving as the swamp smartweed.....we'll see.


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## AaronT (Apr 26, 2004)

I agree with Cavan that you're guess is probably right. Check out www.missouriplants.com or www.alabamaplants.com. They are some of the best websites for identification purposes.


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## davemonkey (Mar 29, 2008)

Thanks, Aaron. I just added both those sites to my favorites.

I am noticing some bumps forming at the top part of one of the nodes of a stem I left floating (not sure if it's root tissue or not, too early to tell), and a root growing on a stem I planted. I'll let some more time pass and then get updated pics if they are still alive by then.
The emergent growth has not rotted or faded away yet.

-Dave


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## davemonkey (Mar 29, 2008)

Update:

The one I left semi-emersed grew new roots and leaves like normal. All the leaves were above water.

The submerged stems gradually died off. Perhaps in a very high light, pressurized CO2 tank they might do well. But, in a moderate-high light with only DIY CO2 (and hard water) they did not make it.

I did run across some P. hydropiperoides, however, and it is doing fine, just growing VERY SLOW.

-Dave


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