The dress of september is made by etsy-vendor: oakhearts . She has a passion for historic clothing and medieval in particular. I discovered that she has studied archaeology some years back, which probably gives her the same background as me.
She said the following about the dress: "I wanted to make something really simple but still beautiful, my inspiration was nature, the forest in particular, somewhat of a forest princess and a bit "robin hood-ish" as if all you are missing is your bow and your ready to go. :)"