What is Stem?

Stem definition and meaning on Dictionary terms:
the ascending axis of a plant, whether above or below ground, which ordinarily grows in an opposite direction to the root or descending axis.
the stalk that supports a leaf, flower, or fruit.
the main body of that portion of a tree, shrub, or other plant which is above ground; trunk; stalk.
a cut flower: We bought roses at the flower market for 50