The term STEM PLANT is composed of two words, STALK and PLANT. STALK is a five-letter word that refers to the stem of a PLANT, which is the part of the PLANT that supports the leaves and flowers. PLANT is a five-letter word that refers to any living organism that is capable of photosynthesis, which is the process of converting light energy into chemical energy. Together, the two words form the term STEM PLANT, which is used to describe any type of PLANT that has a stem.