These grand looking trees (and little sprouts here and there), were originally thought to be Chinquapins, but now we know most Chinquapins are not even true Chestnuts, except one, and it is a rather smallish tree. However, you see that these are quite large and are multi-grafted hybrids probably of Chinese (Castanea mollisima), Japanese, and American (C. dentata) varieties. They're slightly different looking from #20, their leaves being a bit paler. Note again the north-south orientation of this row.

Here's what they look like when ripe. The burrs split open and the nuts -- often 3 of them, one usually the largest -- drop to the ground.