Stemmed usually means having a stem or coming from a particular source.

When we say a flower is long-stemmed or short-stemmed, we're describing the stalk that connects the bloom to the ground. A stemmed glass, like a wine glass or champagne flute, has that elegant narrow column between the bowl and the base.

More commonly, though, you'll hear stemmed when talking about where something originated. If a disagreement stemmed from a misunderstanding, that misunderstanding was the source or root cause. When historians say a war stemmed from economic problems, they mean those problems were the origin. A student's success might have stemmed from dedicated practice and curiosity.

In this sense, stemmed helps us trace effects back to their causes. If your school's new recycling program stemmed from a suggestion you made, your idea was the starting point that led to real change. The word suggests a natural growth or development from one thing to another, like how a plant's leaves and flowers literally grow from its stem.