Fasciation

You'll notice fasciation as a ribbon-like, flat, or abnormally wide stem or branch where you'd expect a normal round or cylindrical one. The malformed shoot may have a braided or bundle-like appearance, sometimes with multiple layers of tissue fused together. Affected branches grow out of place and disrupt the plant's natural form. This condition typically appears on maples and affects the aesthetic shape of ornamental specimens.

Fasciation on maples is usually caused by bacterial or environmental stress during bud development, and it's more of a cosmetic issue than a threat to plant health. The good news is that fasciated stems grow normally and the plant survives fine. Simply prune out the malformed portions if they bother you, or remove the entire plant if fasciation covers too much of the crown. There's no chemical control needed; pruning is your only management option.