Wall Mounted Wooden Shelving Unit

This wall-mounted unit has two wooden shelves with a black metal frame. It measures approximately 23 cm by 10 cm or 9" by 4". Used to hold some of my plants, so the wood is a bit stained from the water+soil. But it can be sanded down and stained. Not sure what kind of wood this is, I’ve had this shelf for a few years. I can include the nails I used, if you’d like.