Art nouveau floor vases "monumental size"

I wonder what year these were made? I can't find the specific logo stamp, green triangle with acorn only & the letters "DUX" under triangle in matching green ink. It appears to be before the iconic pink clay triangle. Could it be one of the first? Family remembers them to the twenties, but has no idea how long before that member had them? I posted them once with other photos here. Does anybody own Dux with this stamp? Again these are 29" tall x 12" wide x 9" deep. I don't think they made a lot this size. They are mystical & so Art nouveau!