I've seen it called a Mexican Poinsettia, but most often it's called Snow on the Mountain. "Euphorbia marginata"

Thanks - very close, and given what you had to go on, excellent. The one I am looking for does not have the varigated leaves. I took a few pictures that may help.

Here is a link that might be useful: Pictures of the white poinsetta

I Googled 'Euphorbia marginata' and see I didn't pay close enough attention to details. Several of my neighbors have plants like the ones you posted pictures of, and I've been blithely assuming they were "Snow on the Mountain". Guess it's time for more research.

Perhaps Euphorbia leucophylla?

Your plant is Euphorbia leucocephala, aka Christmas flower, snow bush, Flor de Nino and Pascuita. It is not a true poinsettia but being a Euphorbia, it is closely related.

Bingo, Euphorbia leucocephala is it, thank you.