Looks like a weed to me... Kyllinga maybe?

Vote two for Kyllinga...

Wow, what I read about this Kyllinga, it will be a lot of work to get rid of it.....$$ &

I've actually found it to be kind of a lightweight compared to nutsedge & spurge--One quick spray knocks it out. If you mulch mow, I think it would get out of hand very quickly given its fast seed production. I bag 90% of the time, so mine never seems to spread but I do get a few patches every year.

I bag also, that's good to know thanks!