Texas Gardening: Plant ID please!, 1 by bellzeybubba

bellzeybubba wrote:
My neighbor has this growing in her shady garden. The prior neighbor planted it, and the current neighbors don't know what it is. It's escaped a bit and is spreading around her yard, growing in both shady and sunny areas. The stems are red on some of them, very pretty. I've been collecting the seeds and I'd like to put it in my yard, but I want to be sure it's not invasive first. Anyone know what it is? Sorry this was the best picture I could get today (borrowing my mother's camera):