Stem

Stem

A stem is one of two main structural axes of a vascular plant, the other being the root. The stem is normally divided into nodes and internodes. The nodes hold one or more leaves, as well as buds which can grow into branches.

Structure and function

Stems have four main functions which are:

• Support for and the elevation of leaves, flowers and fruits. The stems keep the leaves in the light and provide a place for the plant to keep its flowers and fruits.
• Transport of fluids between the roots and the shoots in the xylem and phloem.
• Storage of nutrients.
• The production of new living tissue. The normal lifespan of plant cells is one to three years. Stems have cells called meristems that annually generate new living tissue.

Types of stem

Stems can be either herbaceous or woody. Herbaceous stems only live for one growing season and then die back to the ground in winter. Woody stems live for many years.

Herbaceous stems

Herbaceous stems are green and soft. Stems of herbs are the location of the majority of photosynthesis in the plant. Herbaceous stems are often fast growing and die back to the ground each winter.

Woody stems

Woody stems are hard and not very flexible. Most trees and shrubs have woody stems. The main stem of a tree is called the trunk. The trunk gives height to the leaf-bearing branches, helping to compete with other plant species for sunlight.

See also

• Bark
• Bud
• Leaf
• Root
• Shoot
• Tree

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