Mysterious Stowaway Plant

[Old Scales]

I ordered several plants from the UK about 4 months ago. Among them were two pots of Tropica's Ammania Bonsaii. I planted them and they have grown well, albeit slowly. Right by one of the stems I have this very fine, needle leafed sprig growing. Green and healthy but growing at the same slow rate as the Amm. Bonsaii. It's growing so well it must be aquatic, but it stays so small. I've looked at literally hundreds of plant profiles over the last year and never found one like this. So here's a challenge for you plant gurus out there.
It has a very pretty light green/dark green color. I think it's really cool.
Here is the best pic I can get with my camera. Thanks, OS.

 

[bud29]

A bit hard for me to tell from the picture, but my best guess would be hygro balsamica. Here are a few pictures of, what do you think?

http://www.aquaticplantcentral.com/forumapc/plantfinder/images/Acanthaceae/balsamica.jpg

http://www.aquaticplantcentral.com/...s/Acanthaceae/HygrophilabalsamicaSUPERCTW.jpg

 

[Rivercats]

Yep, Bud's right. It does grows slow but in my 220 the stems and leaves are really thick and heavy and bright green. If it's not bothering you I wouldn't move it as it doesn't like it and tends to pout for a bit when you do.

 

[Old Scales]

Wow! You guys are awesome. This one is only 2.5" tall and is four months old. I really like it so it has a permanent place of honor in its little stowaway position. Another intersting thing to watch. This is why I love planted tanks! Thanks guys. OS.