research with latin names.. will get you a lot further ...

if the second names are not the same.. then odds start stretching .. that the can cross pollinate ...

it would also help if you got a positive ID on those other trees ...ken

ps: i wouldnt have planted a deciduous tree in mid july ..

200 ft is about the maximum distance apart that you could anticipate decent pollenation occurring. You probably need to plant a pollenizer if the others you've seen are farther away than that.

Two chestnut trees on the campus of the community college across the street from my office... probably 500-600 ft apart, with no obstructions between them. Nut production is poor on both - plenty of burs, but most contain only 'blanks' - unfilled nut capsules.

most chestnut species can make nuts together...so hybrid to american OK, hybrid to japanese OK, hybrid to just about any other chestnut is OK. Dunstan is a hybrid.

I almost planted 2 Dunstan chestnuts this year, they are in many Big box stores, I will just say that their tags on each tree said to plant 2 of each Dunstan chestnut trees to get chestnuts. As far as another form/type of chestnut, who knows?

Why not graft a few branches of the polinator onto your tree?