Not grass. Looks like a calla lily. Dig gently until it's gone.

The grass I am talking about is at the base of the tree. It comes from the neighbors yard, long strong white roots. You can use them as rope. I have dug them out previously. Very sturdy

pull a chunk of the grass out and take a pic so we can see it. Though it looks like it could be Bermuda or St. Augustine.

You can spray with this product.
http://www.homedepot.com/p/Ortho-Grass-B-Gon-24-oz-Ready-to-Use-Garden-Grass-Killer-0438580/100355715

Hope the link works. If it does not click then just cut and paste.

I would move the maple further away from that wall.
Roundup carefully sprayed won't hurt the maple.

It's safer to paint it on the offending plant.