The stem is bright red toward the base, and very thick, probably about an inch, which surprised me because the entire plant is only a foot tall. Stem gradually turns pale green toward the tips of the branches. Very shrubby habit, but it's not woody at all, which makes me think it's probably an annual, or maybe a tender perennial. Foliage is light green with willow-like leaves, long and narrow, branching directly from the stem. I was only able to get a decent picture of the flowers, unfortunately, and had to pick one to get even that.
I scavenged this gorgeous plant out of the field where a local landscaper dumps their leftovers. It's mostly just dirt, weeds and occasional expensive stone, but I've picked up some stuff there. Hardy bananas, crepe myrtle, fancy canna, quite a few knockout roses. I don't know this one on sight, though.