Please ID this Plant - Cyperus spp.?

[Puffer]

Got a couple of this plant from NA sometime ago. It has 'needle' leaves and was difficult to be planted into the soil as it keeps floating up (thanks to my horse-faced loach and plecos). After few days, there were shoots coming out and they just keep growing upward. The NA lady boss couldn't tell the name of this plant. Apologies for the poor pic quality.

[CK Yeo]

Same as the plant in this thread.

http://www.aquaticquotient.com/forum...ad.php?t=33758

ck