Sunburn or random variegation

[BaKiBonsai]

Came across this Japanese maple on holiday. It looks like a variegation, a bit like JM butterfly. It's the only branch like it, and it's definitely a branch of the same tree. Sunburn is a possibility but this branch was not really more exposed than the rest.

 

[Boinze]

It looks like the one branch is what is left of the cultivar and everything is is seedling growth from beneath the graft. The leaves look entirely different to me.

 

[Shibui]

It looks like the one branch is what is left of the cultivar and everything is is seedling growth from beneath the graft. The leaves look entirely different to me.

That's my guess too. A grafted 'Butterfly' but the rootstock has shot and is in the process of overwhelming the original grafted cultivar.
you'd need to trace the branches back along the trunk to work out where each bit comes from.

 

[BaKiBonsai]

Everything below it was "standard. This was the only branch like this. Quite high up for a graft, about 1m up on thin branches. It was also more a sidebranch than straight on. The other jm in the garden was identical, but without this interesting leave.

Could be grafted, but it would have been a very weird plant.

 

[Shibui]

Everything below it was "standard. This was the only branch like this. Quite high up for a graft, about 1m up on thin branches. It was also more a sidebranch than straight on. The other jm in the garden was identical, but without this interesting leave.

That makes it a very interesting plant.
Variegation can be genetic or the result of virus.
We see occasional spontaneous genetic changes where just one part changes. Some garden cultivars are the result of these 'witches broom' growths.
Viral infection is more common.
In either case, it would be a new cultivar if you can confirm it's not a graft. Could be propagated by grafting, cuttings or layer to see if the variegation is stable.

 

[BaKiBonsai]

Yes I am curious, I did look at the attachment an it did not look like the grafts I know, but I didn't have the time to make a picture or look carefully.

I think without further information this remains a riddle, and it is too far for me to check up on it. I've added the latitude and longitude below for anyone who is curious (and close). It's in a private b&b garden, on the east side of a small pond.

Location;
51,3310836, 6,1683059

 

[Deep Sea Diver]

Most likely a Butterfly maple. We have one, it does the same thing. All branches are above the graft.

When the plant is young it will often have branches of green coloration and some with the variegated color of a Butterfly.

Cheers
DSD sends