It's growing in NY state if that helps. Thanks for looking!

It looks like buckthorn, Rhamnus cathartica:

Ah, thanks for the welcome! Looks like it. I was hoping for Aronia!

Unfortunately Rhamnus cathartica is an invasive weed, listed as "noxious" in some areas. Birds like it though.

Usually Buckthorn has some wicked thorns on them. Difficult to tell from the photo.

Buckthorns only have one small but strong thorn at the tip of each branch, as the growth on that branch stops for the season. There are male and female trees, and the females like yours, chewycwook, are the worst because they produce the seeds that invade native environments.

very helpful folks here. I will have to keep an eye on her and try to prevent the babies from taking over the yard. I do find it an attractive plant.

The problem is that most of the berries are getting eaten by birds and carried away, and seeds excreted (and planted) somewhere else. That's great that you can watch your yard, but that's not curbing the spread of the species.

Leftwood said:The problem is that most of the berries are getting eaten by birds and carried away, and seeds excreted (and planted) somewhere else. That's great that you can watch your yard, but that's not curbing the spread of the species.

I wouldn't plant a tree that is considered a weed, but chopping down one that is several years old and mature doesn't seem quite right to me either - is that what you're suggesting? Is the plant not local to begin with and is starting to take over around here? I have never seen one before. Seems odd to me someone would seek out to plant a tree like that that doesn't even have edible fruit.

It's not native to North America, and is alternate host to a rust disease of oats - I see the rust on the buckthorns around here. Buckthorn is very common here in Ontario. You can read more about it in this assessement from the US Forest Service:

http://www.fs.fed.us/database/...

If I might nudge your way of thinking, yes, that's kinda what I was thinking... but didn't actually say.
The tree very well could have just grown there as a volunteer, or planted by someone that didn't know what he was planting. Lots of people grow trees for showy, inedible fruits: an ornamental crabapple for example.

If you really want an invasive buckthorn, grow a male that won't spread seed. And yes, cut down the female buckthorn that does spread seed. If you live in Canada or the USA, the tree is probably listed on the state or province's prohibited species list. It's a tree from Europe and Asia, not North America.

Looks like Common Buckthorn to me too; invasive for many areas, N.Y. state as well:
http://www.nyis.info/index.php...
https://www.nps.gov/plants/ALI...

On the prohibited list for N.Y.: http://www.dec.ny.gov/docs/lan...