this looks like nut sedge to me
if you mow your yard and 1-2 days later it has light green tall spikes from it the that is probably it.

to remove them do not pull them you are leaving a nuttlets behind\. they will grow back with more vigor than before.

use sedge hammer or trimec plus to manage them. also bayer makes a all in one weed killer that might work to manage.

if you want to you can use roundup but you will need to paint it on the leafs or you will kill everything around it too.

hope this helps
Gary