Stems transmit food, water and minerals throughout the plant. The roots absorb the water and minerals, and the stem sends it to the leaves and the bud or flower. Meanwhile, the food produced in the leaves is sent through the stem to the bud and roots. According to the Missouri Botanical Garden, stems are the plumbing system of the plant. Woody stems are reserved for those plants that must survive from year-to-year, like trees. The wood acts as a protective barrier to the more fragile inner tissue of the stem. Plants that only need to last for a year, such as flowers, have herbaceous or soft stems.
Although many plants have stems, not all of them do; for example, mosses have no stems. Other stems are considered modified stems because they do not look or act exactly like regular stems. Some of these modified stems grow underground and are edible, like potatoes. Many stems are edible or make edible products, like the maple syrup of maple trees and the sugar from sugarcane.
A woody plant is a that produces as its structural tissue. Woody plants are usually either, or. These are usually whose stems and larger roots are reinforced with wood produced from secondary.
The main stem, larger branches, and roots of these plants are usually covered by a layer of. Wood is a structural adaptation that allows woody plants to grow from above ground stems year after year, thus making some woody plants the largest and tallest. Wood is primarily composed of xylem cells with made of and. Xylem is a which moves water and nutrients from the roots to the leaves. Most woody plants form new layers of woody tissue each year, and so increase their stem diameter from year to year, with new wood deposited on the inner side of a layer located immediately beneath the bark.
However, in some such as and, the wood is formed in bundles scattered through the interior of the trunk. Woody herbs are that develop hard woody stems. They include such plants as and certain species in family. These herbs are not truly woody but have hard densely packed stem tissue. Other herbaceous plants have woody stems called a, which is a thickened stem base often found in plants that grow in or dry environments. Under specific conditions, woody plants may or may in time become. The symbol for a woody plant, based on by is, which is also the for the planet.