Accent plant identification

[Beng]

I have a silverberry with a unique grass growing on the surface of the pot. It must have grown while I was on the east coast as I don't remember it being here when I was out in california last.

Can anyone identify it? It has shallow roots and doesn't seem to be harming the silverberry in the least. I'm thinking it might make a nice accent plant as it appears to have flower buds forming.

Ben

 

[garywood]

Ben, Chondrus crispus Irish Moss. It's terribly invasive but it does flower,white.
Wood

 

[Beng]

Thanks, guess i'll remove it from the silverberry then and give it it's own pot.