Unusual Nuts: ID Contest

One of the most exciting things about food writing is stumbling upon something you've never seen before. Even more thrilling is the food you have actually written about but never tasted. These lovely nuts just happened to be featured among the several thousand vendors at the Fancy Food Show (still on in San Francisco). They are somewhat soft and buttery. A little sweet. I didn't set out to find them. In fact I wrote precisely about how they were introduced to the US about a century ago and then mysteriously disappeared. There were political reasons for this, I think. If you can identify them and tell me where they come from I'll send you a copy of the book NUTS: A HISTORY when it comes out. When that will be I can't promise since the publisher (this is in the Edible Series) has been inexplicably sitting on it for the past 6 weeks. But it's in the line up. And there you'll find the full story. But for the moment, who can tell me what these are? First correct answer, including origin, I promise a copy when it's printed.