Summary:
- In vascular plants, stems are the organs that hold plants upright so they can get the sunlight and air they need.
- Stems also bear leaves, flowers, cones, and secondary stems.
- These structures grow at points called nodes.
- At each node, there is a bud of meristem tissue that can divide and specialize to form a particular structure.
- Figure below shows examples of stem specialization.
- With specialized stems, plants can exploit a diversity of niches in virtually all terrestrial ecosystems.
- The number of rings in this cross-section of tree trunk show how many years the tree lived.