Hidden stems
The stems stored inside an earthly branch, counted even though they are not written on the surface.
In one sentence
The stems stored inside an earthly branch, counted even though they are not written on the surface.
How it is used
They are why a chart can hold more of an element than the eight visible characters suggest, and why a star that looks missing can still be working. Each branch stores a main stem and often one or two more, with the main one weighted most. Schools differ on how much the minor hidden stems deserve, so two readers can describe the same chart as balanced or as short of an element.