It could be a cherry. I have wild cherries and the leaves look like that. Going from memory because it is winter now.
If it is a cherry the crushed leaves should have that strong, distinct cyanide-compound smell.
I don't know the answer to your question, but it gave me a chuckle. A few years back, when I was trucking with Jeff, we were going down the road eating Bing cherries. We were spitting the seeds out the window. We started laughing that years from now, we would be going down this same road and there would be cherry trees growing along the roadside.
I've noticed a second such small tree/plant inside the enclosure.
I had fed my group some about 8 months ago.
I saw a cherry tree in Connecticut once.
I'm not even sure they grow this far south. I've never seen one here. Just the Suriname "cherry" plants.