This intriguing tool is used by a food expert friend when hunting for mushrooms in a local forest. I understand it is make in Italy. The brush is used to clean the mushroom of dirt.
I photographed the tool in a basket of pine mushrooms collected by my friend. The lighting is available light. I used an iPhone 4S and applied minimal processing. This shows the quality that is possible if you understand the limitations of the iPhone camera.
You may buy a copy of this image as a greeting card at http://www.redbubble.com/people/alexhowen/works/10144206-mushroom-knife