The National Grove of State Trees is a good sized area, ~30 acres, at the Arboretum that's laid out in a grid so that each of the fifty states has a square in which specimens of their state tree are planted. No, Hawaii's trees aren't hardy.. Quercus virginiana, the Live Oak, is the state tree of Georgia. Pecans, Carya illinoiensis, is the state tree of Texas.
Every year, come fall, I monitor the Pecans checking every week or so to see if they've ripened. They don't ripen well here, but again this year is an exception. The trees were loaded with nuts and most of them were ripe. Now I've been watching those trees for 8 years now and typically the trees have a few hundred nuts total; of these most abort or fail to ripen. Today I grabbed a dozen quickly and almost all of them were ripe and delicious. I don't know why this year is better than normal. Maybe the trees need to be a certain size to bear well, maybe ripening has to do with cumulative heat, maybe last year's wet fall and warm winter. Who knows?