Maples are strange. For example, if you use bonsai techniques on red maple, Acer rubrum, the leaves will reduce, but the leaf petiole remains full size. This gives you an odd looking tree, 1 to 2 inch leaves held way out on 2 to 5 inch long petioles. Other maples will have other issues. The short list of maples that work well is the Palmatum section of the genus Acer, this is the list Osoyoung stated: Acer circinatum, palmatum, shirasawanum, japonicum, pseudosieboldianum, sieboldianum. A. palmatum is the one that is most successful in creating smaller sizes of bonsai, the others are best in the medium to larger bonsai sizes.
For Acer species that are not in the palmatum group, to create a convincing bonsai, you need to plan to go large. Shoot for a tree that is over a meter tall, at least 3 feet tall, taller is better. This will not require as drastic a reduction in vegetative parts to look reasonably well proportioned.
The "Best Feature'' of A. trifolium and A. griseum is the exfoliating bark. Shoot for a tall design that shows a lot of trunk, to show off the exfoliating bark. Better yet, plant it in the ground, as a focal point landscape plant and use Niwaki training to give the tree an artistic presentation. In case you are not familiar with Niwaki, that is the parallel to bonsai art, where the tree in the landscape is trained and shaped. Essentially bonsai planted in the ground rather than in a pot.
Klehm's Song Sparrow Farms - does have a F2 hybrid from Acer griseum that looks interesting, on its own roots. But as said before Acer griseum does not submit well to bonsai techniques.
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