Texas Gardening: Is this a weed?, 1 by Pam_in_Texas

Pam_in_Texas wrote:
It almost has to be since it's growing several inches each day. I'll provide a little background. I began seeing a plate-sized patch of shoots, purplish red in mid February that really didn't start growing until a few weeks ago. I don't remember if I planted something last year that I thought had died. There was a huge sunflower that grew in this spot last spring and summer, I didn't think the leaves were the same, but maybe it's a sunflower?

Closeup of leaves: