Difference Between a Tree Node & Bud

Basic Stem Structure

• When you look at a tree twig, you see the basic working unit of a tree. The twig provides the framework for getting water and nutrients from the tree's roots and for growing leaves where they can reach sunlight and photosynthesize. Food from leaf photosynthesis is piped back into the stem to be conducted around the tree in sap. The twig has little pipelines in it, called the vascular system consisting of phloem and xylem, which conduct fluids up and down the entire tree, interconnecting everything. Phloem conducts fluids downward, and xylem moves fluids upward. Twigs contain areas of cells that can produce new growth each year called buds, and the buds give rise to leaves and flowers as well as branch elongation.

Buds

• Break off the end of a tree branch and look at the very tip of the branch. Located there is the terminal bud, which will grow into a new branch tip. Along the branch are lateral buds that will grow into leaves or side branches. In an already-leafed-out branch, the buds have expanded into leaves. In the space where a leaf joins the stem, or the leaf axil, another bud or latent bud may not be visible. Called the axillary bud, it can grow into a new branch or produce flowers and fruits.

Nodes

• The areas of the stem that hold the buds are called nodes. The bare stem spaces between the buds are called internodes. Internodes can be long or short, depending on the type of tree and the conditions during its growth. Full sun exposure produces shorter internodes than shaded conditions produce. Vigorously growing plants have longer internodes than slowly growing plants. Dormant buds growing from the nodes can be either flower buds or vegetative buds that give rise to leaves or branches. Flower buds tend to be rounded at the tip and fatter than vegetative buds, and vegetative buds are more narrow and pointed.

Growth Cycle

• Each year, plant hormones respond to the change in seasons, including hours of daylight and temperatures. During favorable periods, hormone production increases, causing buds to expand and grow. During unfavorable periods, such as the cold of winter or summer drought, leaves can drop and the tree can become dormant. When favorable conditions return, tree nodes produce new growth. Unlike animals, plants continue growing during their entire lives thanks to the built-in growth potential at each node. Control a tree's shape by removing branches back to the main stem, or trunk, so that no growth can continue from those particular nodes. If you want to encourage branching, remove the tip of a branch back to a lateral bud that grows in the direction you want new growth to take.