could this be a A. japonicum hybrid?

I get scads of J.m. seedlings in my coastal Maryland garden. These are mostly found near a huge 'Bloodgood' type JM planted in the 1960s. I let this one grow because it has a beautiful, prolonged bright-coral fall color, almost fluorescent seeming. (it is green most of the year) It also grew exceptionally fast. I have a 'Mai kujaku' aka 'Aconitifolium'. Does this look like a hybrid to the experts here? I guess the flowers would help, can post those in the spring.

 

To me, it looks like an amoenum.
Since 'Bloodgood' is a cultivar of amoenum, I suppose this is from a seed that has reverted to green, with some autumn characteristics of the autumn colours.

Do you have photos of the "bright-coral fall color" ?...

 

Agree with everything Alain has said in his post #2.
Not a japonicum hybrid IMO.

 

Acer japonicum can usually be distinguished by downy hairs particularly along the veins on the leaf undersides and stems. Would a hybrid be expected to maintain the hairiness of the A. japonicum?

 

OK, thanks for the expert opinions. Even if just a random seedling, it's nice. I guess I thought it was possibly a hybrid because it seems like most of the seedlings of that Bloodgood/Emperor type maple have red leaves, all year, this once is green and then goes to a distinctive type of red. Also the typical seedlings turn out to have red "stem bark", not green like this plant. In general you really have to see it "IRL" to see why it stands out, but here's a pic from last fall.

 

Now that I look around my garden - I've let several other seedling J.m. grow out for evaluation or just to fill space - I wonder if what I thought was hybrid vigor might simply be that a green-leaved plant can do more photosynthesis and therefore grow faster? Is it generally true that, all other things being equal which of course you cannot guarantee - most green-leaved Japanese maples will grow faster than red? it's certainly known that yellow slows growth...Illicium 'Florida Sunshine' is growing very slowly versus other Illiciums of mine.

 

I have found both green and red Japanese maples to grow equally throughout the year. Depending on the variety and similar position and soil of course, around 36 inches for some of mine.

 

Thanks for the further replies. OT, but note the distinctive looking scars of 17 year cicada damage in the picture of the trunk.

 

And Acer japonicum have not green bark. Young amoenum have such a green bark during first years.

 

I'm sorry to prolong this, but trying to square this: "Acer japonicum have not green bark".
Here is what I thought might be the pollen parent. I believe it is the cultivar 'Aconitifolium'. Is that not green?

 

Here is my Acer japonicum Aconitifolium a few minutes ago. You can compare with yours David.

 

Yes, you are right . I beg your pardon.

 

So the conclusion I'm to come to is the plurality of 'Emperor'/'Bloodgood' type seedlings will be reddish of some sort, and have purplish-red fall color...but a minority might revert, without hybrization, to be 100% green during the growing season, and have a more orange/salmon fall color?

 

The thing with seedlings is. you never know what you will get. That is one of the fascinations and one that profesional growers look out for.

 

I've never had seedlings from 'Bloodgood', but I found that this happened with 'Atropupureum'. So that might well be the right conclusion, yes.