A.p. Shaina will not flower because it is a witches broom. These mutations are almost always sterile. A good way to tell if its a witches broom is the shortened middle leaf lobe on many of the leaves. Some people call it a "crab-leaf", because it looks sort of like a crab.

My Crimson Queen flowers every year. Grafting does not keep a plant from flowering. To the contrary, if the graft was taken from a vigorous part of the mother tree that was prone to flowering, it may flower in its first year. If the graft was taken from an older part of the mother tree, like a lower branch, it may take a long time to start flowering.

Seed grown trees flower much later - after many years. Just be patient and your trees will flower and produce seeds as well. The seeds will not produce exact copies of the parent tree, just as your children aren't carbon copies of you. But you can get some interesting results and its really fun to grow them and see what turns up. This is how most of the 1000+ varieties of Japanese Maple were found - chance seedlings growing in a garden or nursery that had unusual or different characteristics from the norm.

Kaitain....thanks for the info...I've been waiting for someone to bite on this one!! So would it be safe to say that the particular genetic mutation responsible for the expression of the witches broom phenotype is also responsible for the sterility found in this particular cultivar? If and when my dissectums begin to produce seed, what are the chances the seedlings will be dissected? Are they more commonly of the classic palmate variety associated with the root stock? For some reason I wanted to think that grafted plants were sterile...learned something new today...thanks