Martin, just wanted to mess with you.
It came from a reputable private collection in northern San Diego County. I have not seen fruit yet, so do not know it it was correctly labeled. Have to give it the benefit of the doubt for now, but time will tell.
Interestingly, I have a friend with a "Black Ishi" tree which may be a true Black Ischia. The trunk is about 6" in diameter, but it was in decline and growing poorly when I last saw it. At one time is must have been quite an enormous tree.