Genetically they are very similar and so able to hybridize. Shirasawanums in general tend to have larger, more circular (but also heavily lobed) leaves, hence the common name of full moon maple (as are their very close cousins, Acer japonicum). It also has samaras that are held erect rather than hang down (as do the palmatums).

As with all the Asian maples, each cultivar offers its own attributes and should be judged accordingly :-)) I have a couple of shirasawanums and have also grown japonicums along with my collection of plamtaums. Acer shirasawanum 'Aureum' - the golden full moon maple - is a stunning, glowing tree that should be considered by any Asian maple enthusiast!!

I have an Autumn Moon maple, and I'm contemplating digging it up and making a bonsai out of it. A few winters back the right part, including the main leader died. I staked a branch to form a new leader, but it just looks weird.

I really like it though. VERY beautiful and colorful tree! I'll probably get another to replace it.

The former is generally more hardy. Jordan is a fantastic cultivar.

whaas_5a(5A SE WI)

The former is generally more hardy. Jordan is a fantastic cultivar.

I have a Jordan that's maybe 6.5 ft tall. It's been in the ground a couple of years and so far I'm not thrilled with it. I does have a pretty green but that's all I've saw. Last year no fall color to mention and this spring was nothing spectacular either.

Maybe I have it in too much shade.

David, it sounds like yours is in too much shade. Mine gets full sun from about 8 am till 1 pm and it's a yellow color.

Mine was in full southeast exposure.

The JM in my profile photo is a shirasawanum. More and more, I'm starting to appreciate the beauty of the shirasawanum cultivars. My favorite is Moonrise. It has a lot in common with Autumn Moon, but in my experience it's a tougher, easier-to-grow cultivar. Very healthy, very even structure, and amazing color all spring and summer.

They are considered more hardy than Acer palmatum cultivars. I grow in 5b, but even in the polar vortex winters that were more like 4b in their temps, Moonrise didn't have any dieback.

I also have Bashful, Yasemin, and Johin, and I love all of them for different reasons. Very beautiful trees.

I have both palmatum and shirasawanum in my backyard planted last year. They are about 15 feet apart. The palmatum cultivar is fireglow and shirasawanum is autumn moon. I would say the autumn color of shirasawanum is pretty insignificant, unlike the palmatums. But its when the shirasawanum first leafs out in spring its the most appealing. Also, in my experience the shirasawanum is more tastier to deer than the palmatums. They've eaten my shirasawanums but the palmatums that is right next to it barely gets touched.

I'm not sure if one year old trees and only a single cultivar of either species is providing enough history/experience to arrive at that conclusion :-) 'Autumn Moon' is so named because of its fall coloring! And other selections are also known for impressive fall color as well. As with the palmatums, the variety and intensity of the fall color will relate directly to a specific cultivar and to siting.

My experience mirrors heruga's. I'm not impressed with Autumn Moon's Fall color. So much so I traded it away to my neighbor years ago. Spring color, however, is outstanding!