Can you identify .. . . . ??

Hey, a friend sent me some clippings of this plant and they have gone wild!! Problem is, I don't know what they are. Anyone hazard a guess? Thanks!!! (It's the tall stalk with pointy leaves @ 1.5 inches, leaves turn slightly red at top of tank where light is. 29g, 17w light, lowlight plants). I thought maybe a rotala, but their stalks look thicker. Flourite substrate, plant tabs.:help:

Thanks ya'll, I'll look up the hygrophila.
The red orange fish are Neon Gold Rosy Barbs--all natural, no dyeing, genetic mutations, etc. A bit pricey, but they offset my one planted tank very nicely!! Found them at PetSmart, very healthy (we have a good one), $5.99 each. Maxed out around 2"; three have long fins, three have short. They "dance" beautifully, in pairs or 4s ("the orgy dance"), very entertaining. Typical barb piggies; I just ignore it!!! The tank is more spacious than it appears in the photo, but considering how they are growing, I think bunching the plants would work well--thanks, PBM. A nice balance to all my cichlids .. .

Definitely hygrophila!! A very invasive plant in Texas and Florida in the waterways. Great for a lowlight tank!! Woot!!