Natural forms like that can make very nice containers for plants. I don't know if there is room on the underside to hollow it out and seal it at the bottom to hold sufficient soil, but I think it could be attractive indoors or wherever. You could line it with some water impervious sheeting to keep it from rotting. In the very least, and simple, it could function as a vase, with a piece of wood on the bottom and holding a glass for water. I can't really tell how tall it is, but it occurs that cutting it down might make it more purposeful to use for a vase. If you were to smooth off or maybe just wire brush the top, it would be a different effect from leaving it all natural, could be interesting to play with.
The photo is something kind of similar just to give an idea, made from a piece of Persimmon. I just shaped the upper portion a bit on my lathe. It looks nice with some flowers or greenery in it sitting in a glass. The roughness like with what you have, Wille, gives a nice contrast to a delicate plant arrangement set inside. The one I made must be about ten inches tall by eight inches wide. After shaping it and sanding, some oil brought out the color of the wood.