There's a Triticum turgidum var. mirabile, which sounds like it might be the variety he found.
According to an article I found from 1951[0], it used to be popular in the Mediterranean, and the seeds can germinate after long periods of storage.
I also tried to look at the wheat in the picture, but not the highest resolution, and it looks like it might be more than one variety, which he did mention. But at least some of the heads resemble the mirabile variety.