The term 'flower stem' can be broken down into two crossword solutions: STALK (5 letters) and PEDICEL (7 letters). A STALK is the main stem of a flower, while a PEDICEL is the stem of an individual flower. Stalks are typically thicker and more rigid than pedicels, and they are usually the part of the flower that attaches to the plant. Pedicels, on the other hand, are thinner and more flexible, and they are the part of the flower that attaches to the STALK. Together, the STALK and PEDICEL form the stem of the flower.