Hence the name 'Summer Poinsettia'!

Lovely well-grown plants, snasxs!
I planted a few of these myself this year.

Very pretty Snasxs!! Thanks for posting the name for us nanw...I have never noticed these plants before in my stores/nurseries. Very accurately named!!

I've never see this anywhere -- cooly bizarre --- so it's a Euphorbia like Ponsettia are?

I think it's an amaranthus, actually. There is a weedy euphorbia growing wild in our area that's sometimes called "Summer Poinsettia," but it's not this plant (E. heterophylla, I think). It looks just like a smaller, more slender poinsettia in which the orangey-red just colors the base of the bracts (I seem to recall a yellow band just past the red as well).

These are very easily grown from seeds, and the seeds are fairly easy to obtain, and relatively inexpensive, too!