A tree-like grass inflorescence:
My best guess is that the grass is Panicum philadelphicum or another Panicum species. For some reason, the common name of grasses in this genus is panic grass. Maybe panicled grass is too many syllables! It’s a large inflorescence, at least 18 inches. The background is red-osier dogwood. I spent some time to key it out, it probably is Swida sericea, and not another Swida species. The showy vertical stems offered some nice winter color.