Plant id please

[simon Coram]

I bought a bunch off VALLISNERIA when my LFS was closing down and in amongst it was something similar looking but with stiffer leaves/ stems.
http://[URL=http://s138.photobucket.com/user/rustydiver/media/B102CD7F-0377-453A-8E56-9E455B61C372_zpsbtrmxiti.jpg.html][ATTACH=full]94162[/ATTACH]
[ATTACH=full]94162[/ATTACH]
It's the stuff behind the algae ball.

 

[Nelson]

Cyperus helferi ?.

 

[Mick.Dk]

Cyperus helferi or Achorus graminea both look like this.

 

[simon Coram]

Achorus graminea

Thanks it looks like this one.

 

[tim]

Thanks it looks like this one.

Not sure it'll do well underwater long term if that's the one, I stand to be corrected.

 

[Mick.Dk]

Achorus have the reputation of not surviving submerse long-time.
- However, I have an Achorus sp. (presumably graminea), that have now been sitting in a really Low Tech tank for 2 1/2 year. Absolutely low ligjt of less than 0,5 w/l, no added CO2 and low dosage of fluid fertiliser. That's it........
The really remarkable hing is, it not only survive, but actually thrive and grow. From one, straight "rhizome" carrying about 6 leaves - to a huge plant of 40+ cm. now supporting about 10 "branches".
It may take atmospheric CO2 from leaves laying in surface, though.