I've just realized that I don't know of a single one good for zone 4 or
colder. The closest thing to this that I do know is the seeds of most
fruits such as apple, pear, peach and apricot have a small amount of oil
and the seeds themselves are inedible because of the cyanide content.
The composition of persimmon and pawpaw seeds needs to be checked on.
[permaculture] Perennial Nonedible Oilseeds,
Jay Woods, 03/09/2011