There is something very prehistoric looking about this tree. The leaves are below.
I looked in several tree identification sources. I wondered if it was some kind of nut tree judging by its fruit. One slight obstacle in identification is that trees in arboretums aren't necessarily from this country so I may have to go back and see if it's labelled, however I'm leaning towards it being some type of hickory.
References
Images
Photos from my Canon SX620 HS at the Central Experimental Farm's Arboretum, Ottawa, Canada.
