There were grapes growing as if they were growing from the tree, but actually they were growing from the grapevine that twined around the tree.
Then I noticed that the tree itself also had fruits. The fruits looked like grapes, and I looked back several times to check if these fruits were really growing out of the tree itself.
I took a picture of the leaves for help with identification:
When I got home, I noticed that there was a similar tree next to my driveway.
On August 18, I happened to be reading about plum trees in The Sibley Guide to Trees, and it struck me that what I was reading matched what I had seen: shrub or small tree in thicket, bark brown with lenticels, and small round fruits.
On August 27, at the bike path again, I photographed a different tree which seemed to be the same kind:
Buckthorn
Nannyberry
American plum
Canada plum
Pin cherry
Choke cherry
When I got there, I saw what seemed to be the same tree, but what was clearly evident was that its leaves were opposite. That rules out plum and cherry. In the photos in Trees of New York, the fruits of nannyberry hang down more, not matching the tree I saw. That leaves buckthorn.
When I try to identify the tree using the Arbor Day Foundation's What Tree is That?, the only choices it gives me for opposite, simple leaves are maple, catalpa, and dogwood. The Tree Identification Book by Symonds lists two more choices besides maple, catalpla, and dogwood: paulownia and nannyberry. The tree I am trying to identify does not match any of the choices in What Tree is That, and only bears a slight resemblance to nannyberry in The Tree Identification Book. No wonder I find trying to identify trees using these books frustrating.
The Sibley Guide to Trees is not organized by which trees have opposite, simple leaves, but now that I have some possible names from Trees of New York, I can look up nannyberry and buckthorn.
Sibley lists nannyberry under the name rusty blackhaw. It seems not to be the tree I am trying to identify because 1) it does not usually live in the northeastern US, 2) the fruits hang down more, and 3) the leaf veins are different.
It says that buckthorns may have either opposite or alternate leaves. The book mentions two types of buckthorn and four types of false-buckthorn. The one that seems the most likely candidate to be my tree is called European buckthorn, common buckthorn, or European waythorn.
The Sibley Guide to Trees says of common buckthorn, "low, rounded crown of tangled twigs and small dark leaves." It says the twigs are thorny, and the leaves are "finely toothed, often with 3 main veins from base and veins follow leaf edges."
I compared the tree by my driveway with these statements.
- I did not particularly see a crown. There are twigs with leaves all over the place. There is no rounded shape to it.
- I could see what they mean about thorny twigs, on a few twigs, just a little bit.
- I'm not really sure what "veins follow leaf edges" means. There's a vein going down the middle, and veins coming off the side of it, which is what they call pinnately veined. But the veins that go out to the side don't go straight out to the side, they are angled toward the tip of the leaf. So if that's called "following leaf edges" then that's what they do. The side veins seemed to be alternate rather than opposite. Perhaps two side veins that start closest to the base, plus the middle vein are what they call "three main veins from base."
The fruits in the tree by the driveway struck me as smaller than the fruits on the other similar trees I observed. On the first tree I observed, I thought they looked like grapes, but in the tree by the driveway, they seem smaller than grapes.
So for now I'm concluding that this tree is a buckthorn.
In high school science classes, they told us about the scientific method, told us that science was not about memorizing facts, but about forming a hypothesis and making observations to test that hypothesis. But in the "experiments" they assigned us to do, they always told us exactly what amount of what chemical to add in what order. We never really figured stuff out. Despite lip service to the contrary, what we really learned in high school was to do as we were told. But now, out in the real world, I'm finally trying to figure stuff out, as I try to identify trees.
