I've got a bunch of Alternanthera reineckii growing emersed on riparium rafts in my tank. It grows ridiculously fast and I'm constantly pruning so I have a steady supply of stems if anyone wants them. I don't really want to deal with shipping at this time so this is only for local pick up.
It's the plant in the foreground. The leaves were solid red/purple when I first got a couple of stems from hydrophyte but it seems to grow green leaves in my setup (presumably something to do with my lighting).