And yet, I do believe it is the same plant. I have 5 Karls planted around the perimeter of my firepit, and from the background shown, near as I can tell both photos are of Karl in different stages, and they are both labeled Karl in my Grasses photo folder. But to confirm this, here's what I will try to remember to do: next season I will take photos of Karl using the same plant and same angle with a distinguishing rock in all the photos (they are all nestled among boulders). First, I will shoot the entire plant, then a close-up of the seed heads. Kind of like a time lapse. I'll put a note in my calendar to remind myself. Should be interesting.
Please also reference database photos submitted by Jill, Admin, Treehugger, DebbieC, and Molinic.