No, this is not a hackberry. It could be a walnut.

Leaves of the Hackberry are alternate, not opposite. The leaves are also lope-sided. One curves down and the other curves up at the base. Leaves are toothed, too.

Here is a link that might be useful: Hackberry Ulmaceae Celtis occidentalis

It's not a walnut, I have lots of those and this is different.

It is strange, but like I said, the top branches are alternate - but the branch I photographed had opposing leaves, I guess I should picked a different branch. The leaves are lobe-sided - look at the leaves in the lower right corner and you can see it - granted not drastically lobed but somewhat. And the leaves are slightly toothed but not deeply toothed. I think that is why I am confused!!

What you've taken a picture of are several COMPOUND LEAVES, with the leaflets arranged in an opposite manner. They are oddly (an odd number of leaflets) pinnately compound, to be precise. Compound leaves (of many kinds) are very common in the plant world...roses, many types of beans, hickory, walnut, and all of the rest of that tree family, ash, and so on.

I'd say that this is one of the many hickory species, though it could be a pecan. If I could see better how many leaflets are on each leaf, it might be possible to ID this tree for you.

Hackberry does not have compound leaves. Nor do elms.

So do you 'see' the difference between compound leaves and simple leaves? Attached is an image of two types of compound leaves, though there are others.

Here is a link that might be useful: {{gwi:532274}}

Hmmmm...I wish I knew more about trees. It looks like something in the hickory or ash families..Try http://forestry.about.com/od/treeidentification/tp/tree_key_id_hicash.htm

Hackberries look very simillar to elms and have the rough leaves. They are often hard to tell apart. The difference is in how the leaf attatches to the stem. Also, elms look darker and hackberries are often infested with hackberry psylids (that make that gall on the leaf). Hackberries are fuzzy too. I think it is interesting that question marks use leaves that all have the same texture, elm, hackberry, and hops.
Cheers,
Elisabeth

Click here: This is what the key says for compound leaves.

Here is a link that might be useful: Leaf Key from Virginia Tech

Doesn't the bark look more like cherry?

I really appreciate all the help you have provided. I see now that it is definitely not a hackberry tree.

But if it is not too off topic to continue this I would be interested to know if it is a hickory, etc. SO here is a new picture, the leaf on the left is a black walnut, the one in the middle is the same as the picture above, the photo on the right is another mystery tree.

{{gwi:532280}}

Here is what I have always thought were elms ... the one on the left was a slippery elm and the one on the right was an American elm ???

{{gwi:532282}}

The reason I am asking about hackberries is that since I started putting out fruit I now have lots of hackberries and I am curious if the host plant is something in my yard so I've been looking closer at some of the trees that I've never bothered to identify.

Thanks again for all the help!

Last picture, the leaves on the right are a Hackberry. Look at the lope-sided leaf.

Hackberry butterflies spend their entire life near the Hackberry tree. They eat it, they winter over on it, and they hang out near it. It attacts five butterflies that I know of as a host: Hackberry and Tawny Emperors, Question Marks, Mourning Cloaks, and Snouts. Plus, wonder berries for birds.

You original picture still looks like a walnut to me. Young trees can have larger leaves. I've fed enough Black Walnut to Lunas to know.

Oh goody! I am very excited to know it's a hackberry. I have a few of them but they are all rather small (10-15 feet). I have seen mostly hackberrys but also one tawny, lots of question marks, one comma and a few mourning cloaks. I am amazed at how quickly they found the fruit!

I agree now about the walnut - once I compared them side to side, they look identical except for size. The smaller one is a mature tree in full sun, the larger one is a young tree in mostly shade.

Thanks again!

I know a little about trees. I took a class called "Winter Woody Plants". I had to identify trees by their bark and bud scars. Walnut has a little monkey face bud scar.

Here is a link that might be useful: TREE IDENTIFICATION KEY (another good one for identifying trees)