Anyone have a diagnosis? It feels dry to touch, not tacky or slimy. The tree is a beauty. I know the crotch is a problem, but I’d hate to lose it so soon.
Help! Acer palmatum in trouble
Maybe one of the cankers on this page. Some of them say they are dry, at least some of the time. https://www.gardeningknowhow.com/ornamental/trees/maple/maple-tree-bark-disease.htm