tie a yellow ribbon

I was keen to make something outdoors when I went for a walk at the weekend. My son and husband decided they were cold and wanted to go home so I was left to get on with it myself. There were still a lot of autumn leaves on the ground; sycamore, horse chestnut, oak and a small yellow leaf that I can't identify. You can see it in the second and third photos. It has a sort of fruit on it in late summer. Does anyone know? The sycamore leaves were an amazing bright yellow. I tucked some into some ivy that was curling around the trunk of a tree. There is a custom of tying a yellow ribbon around a tree to symbolize waiting love that goes back to Roman times. This tree is at the bottom of a flight of stairs frequently used by dog walkers. In fact I bumped into a friend walking her spaniel and felt a little odd to be standing there, on my own, with a handful of leaves. I also made a little forest sunflower with the sycamore leaves and a horse chestnut shell. Doing an activity like this definitely made me look at my surroundings more closely and notice the different colours, textures and shapes much more than if I was just walking through.