Some plants have woody stems. The plant’s woody stem can also be called a trunk, as in “tree truck.” The trunks, or woody stems, of plants grow outward and become wider every year. Each year, the plant’s woody stem, or trunk, increases in thickness and the tip of the plant grows upward toward the sky above them. This means that the plants with the trunks, or woody stems, get taller every year, as well as getting wider every year. Some good examples of plants with woody stems, or trunks, are trees and shrubs. There are also many vines that have woody stems.
Woody stems have bark, which covers the trunk. They also have a food conducting system, called the phloem. Woody stems have tissue that conducts water and minerals. This water and mineral conducting tissue is called xylem. They also have annual rings, which help in determining the age of the plant. Woody stems, or trunks, also have nonliving wood inside them, called heartwood.
If you have ever been in the woods, then perhaps you have previously come upon a tree trunk that had been cut by a logger. The insides of the severed tree would have been exposed, showing you things such as the tree’s annual rings. If the tree was very wide, then it might have had many annual rings, possibly even over a hundred. That would mean that the tree was over a hundred years old. These severed trees would also have exposed heartwood, which would be found in the center of the rings.
Some plants have non-woody stems. Those plants are called herbaceous plants. Their stems do not have any bark and they are green and supple. Herbaceous plants are similar to plants with woody stems because they have phloem and xylem tissues that transport food and water through the plants. The xylem and phloem tissues are arranged differently within monocot and dicot plants.