Stunning! Looks to me as much like sumac as walnut. Not ash.

Walnut is a tough one to root, I'm reading, wonder about sumac. It would be a shame for this to just get weed whacked!

looks like variegated knotweed below.. and a plastic plant above ...

ken

https://www.google.com/search?q=variegated+knotweed&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjD4YH67q_NAhVSQFIKHbkOA60Q_AUICCgB&biw=940&bih=745&dpr=0.9

Not knotweed, that one has more rounded leaves.

wow @trreeguy123, I wouldn't have ever discovered that. Do you think the leaves will gradually develop green spots, like in a nashiki willow?

Knot-weeds produce undivided leaves.

It could develop green spots if the mutation did not fully loose all the chlorophyll, but the latest growth seems to have lost it.

But how can a root sprout be mutated? It should share all its genome with the mother tree, they are linked together and are the same individual

A bud Mutation will change the genetic genome from that single bud upward.

Rare freak mutations can happen at any time in a trees life. This one happened at the recent new bud that developed off the base of the tree, this does Not change the genetics of the whole tree. :-) It only changed the genetics and any new cell growth from that new mutated sprout bud upward (any new cell growth above that bud.) Some times chemical sprays can cause a mutation. Someone may have sprayed the trunk base which caused the dividing cells of that one bud to copy information wrong thus creating the rare albinism on any new growth off that one bud upward.

New variegated cultivars many times are grafted on top of regular green leaf tree root stocks for example. If the variegated grafted top happened to died, then the regular roots would send up a regular green leaf tree.

Interesting, I didn't know that

whatever it is id love to have one in my garden. reminds me of the "flamingo" cultivar of Chinese mahogany

yep - toona sinensis leaped into my head.

it's not japanese knotweed. the leaf shape and branching resembles that of a black walnut or ailanthus altissima.

Toona sinensis also came in my head, but you can tell several leaflets have notches at the base which is typical of Ailanthus altissima. Also Toona leaflets are more lanceolate shaped (pointed at both ends). Ailanthus altissima leaflets are much more flat the the base like the picture.

It's Ailanthus altissima. That white growth is likely to severely burn in full sun but nonetheless quite a lovely looking variegation for a most hated tree in North America. People passionately despise that tree.

Dax

Looking up Toonis Sinesis, there's no comprable growth habit evidenced here, unfortunately it seems like Dax's @gardener365 ID is most likely ... it's exactly the type of neglected area where these guys flourish!

gardener365, they sprout everywhere in my yard and in my driveway and I have to pull them out and burn them. I really do passionately despise those trees but this one, would actually be neat to have!

I'm tempted to try to separate the sucker hoping it would be weak enough due to the variegation, but then I doubt it would be sterile. Also, it's not even my yard ...

I don't think anyone will care ;). they will probably just cut it down anyway

Yep, sterility came to mind immediately for me when I first saw it. Just another nightmare of a tree once it starts throwing seeds . . .

Later Conor & Caldwell,

Dax

Might have been induced by someone spraying herbicide around the base of the tree.

@vinogradnij I'll take a walk by and see again, its been a few months ... the owner may not be amenable to it but it would be very interesting!

Ailanthus altissima. i just found one all on its own serviving off a couple variegated parts at the base of the plant

I respectfully disagree regarding the Ailanthus altissima of my hundreds of sprouted english walnuts i currently have 7 that are white just like the picture.