Looks like Oak but don't know the species. If you can give your general area of the country in which you are located, might help to narrow it down.

Some variant of Sweetgum? Take part of a leaf, crush/tear it up & smell. If it has a sweetish, resinous smell, could be Sweetgum. An oak would have little smell.

I live in Toronto, Canada.
I've posted on Canadian forums as well, without any luck in identifying.
Two of these trees have sprung up and are growing quite quickly.

White mulberry, asked about repeatedly. Numbers of photos of same kind of leaves and sprouting have been posted, asked about.

To my eye, it doesn't look like any oak, sweetgum, or mulberry I've ever seen.

I can't say what it is.

To my eye, the closest thing it resembles are certain types of hibiscus, such as Abelmoschus manihot, Abelmoschus moschatus, or possibly Hibiscus coccineus.

And it doesn't resemble any images of those I've found all that closely, either. And how those would pop up in a Toronto yard???

I believe it's still a mystery.

Ditto what Bboy said.

Here's what it looks like from a little further back.

Maybe Ficus afghanistanica?

Here is a link that might be useful: Click to compare

OK...maybe not, lol!

Could be some poplar cultivar, maybe based on populus alba

Well, the trunk photo blows my Hibiscus theory out of the water.

I still don't see the white mulberry ID. When I google image search "white mulberry leaf" it adds the search term Morus alba, and nothing on the results page looks like that leaf.

I'm actually going back to the variant Sweetgum theory on the leaves.

But the trunk bark doesn't look sweetgum, albeit photo resolution is poor and dark.

And, what bit of the bark I can make out in the photos DOES seem to be consistent with seedling mulberries in color.

So I'm stumped.

But it's an awesome looking little thing.

So SOMEBODY better solve this one -- we need an ID so we know what to order! LOL!

Here is a link that might be useful: It doesn't look like any of these!

MorusMorusMorusMorusMorusMorusMorusMorusMorusMorus....alba.

As stated above - and on plenty of other websites - this species has an incredible variety of morphologies expressed in its leaves. Depending on whether the leaf emerges from dormant buds or on the new stem growth extensions of the season; whether the plant has been whacked back and is sprouting vigorous new stems, or is a new seedling emerging from the soil. You can see the variations on a single plant - just like the one marlo posted here and another popular ID site.

A Google search is not the final answer. Go see this plant in all its invasiveness just about anywhere in the eastern US - and pull a few out while you're at it.

If not Morus alba, my second guess would be a saguaro cactus (i.e. it is a mulberry).

Well, sorry if I offended. Wasn't my intention.

It just looks so radically unlike any mulberry I've ever seen.

Which doesn't mean much at all, I freely admit that.

Anyway, it is incredibly exotic looking.

Is something with that type of leaf form out there in the commercial trade?

No offense taken, denninmi. I use emphasis to indicate confidence in the ID, and try to provide explanation when there seems to be confusion. That really is the best one can do over the web.

This same post shows up on other sites, and emphasis is provided there, too. Additional imagery closeup on the stems, buds, etc. (including parts like sam_md has provided) would help persuade as well.

Here are a few more pics. I'm solely relying on my phone camera and will need to get my hands on a better camera for more detailed close-ups.
Thank you everyone, for your input! Greatly appreciated.

underside of leaves

branches

M.alba, as previously stated. The trunk photos cinched it, if I'd had any doubts.
I could take you right now to several similar M.alba seedlings, growing in/through the chainlink fence surrounding the parking lot at the local high school, and show you no less than a half-dozen with that same deeply-lobed leaf morphology.
Those remind me, to some degree, of some of the Brunswick/Magnolia-type figs(also members of the Moraceae).

Thank you again everyone for your input.
For anyone still interested, i'm attaching some clearer photos...

hollow branches?

new sprouts

Mullberry. I've been fighting them for years. Bark and hollow trunk the same. Leaves a bit different, but it's a mulberry of some sort.

Yeah, the bark caught my attention, too. Mulberry.

vince

When you snap a twig, does it exude a milky sap?

Even though it's way out of it's native range it sure looks like Morus Microphylla.

FWIW, even though I myself have commented in the past right here on this board about Morus' variable leaf shapes, even on the same tree, I've never seen one like that. Which is not to say I don't agree that this is what it is. Just kind of an oddity within my experience.

+oM

marlo:

Thank you for the additional vivid images - those are great, and aid in convincing the ID.

Do everyone a favor. Put a note on your spring 2013 calendar to take pictures of the new leaves as they emerge and harden off on this plant. You will be amazed that they are from this same individual that has such strikingly odd foliage this summer.

Chinese Mulberry, particularly tending toward the variety referred to as the 'Chicken Mulberry' because of the leaves resembling a chicken's foot. Morus australis var. linearipartita

If not Morus alba, my second guess would still be a Carnegiea gigantea.

marlo23 - Has this ever actually borne any mulberries? And if so, what did they look/taste like?