They are similar in nature to a Tuber Melanosporum, but not actually related. They are not an equal substitute for a Black Truffle, White Truffle, or even a Chinese Truffle for that matter. A hotel I worked at that was owned by Arabs had a large stock of them, canned. Popular in the middle east but no discernable flavor as near as I could tell. Don't bother with them unless you're doing something for middle easterners who might appreciate them.