What does a practicing arborist recognize as a node on a tree stem or branch? Botanically, defining a node is simple and based on primary growth. In the seedling or newly emerging shoot, growth is from cells produced at the tip by the apical meristem. Based on the genetic program, a leaf is produced every so often and in a specific arrangement. In the leaf axil, the upper side of the angle between stem and leaf, a bud is formed. Let’s call that an axillary bud. The node is located at the connection of stem and axillary bud. The length of stem between nodes is termed the “internode”. Yes, very creative. Okay then, the axillary bud breaks dormancy and produces a new shoot with its own tip meristem. In woody dicots (“regular trees”) the vascular cambium forms and “secondary” growth ensues in branch and stem. That branch is certainly located at a node. Now not all of those axillary buds germinate and sprout. Some cells divide just beneath the bud base and move the bed along outward in the bark, just to the outside of the stem vascular cambium. It can be mighty hard to see those latent buds, but they are still at a node. There is still a “bud trace” in the wood that shows that these are axillary buds. As the stem or branch increases in girth due to wood production, new buds may form along the stem surface at locations other than nodes. These are defined as adventitious buds. There is no bud trace, there is no node. Sometimes meristematic points are formed without the protective scales characteristic of buds. These adventitious buds and meristematic points may or may not germinate and sprout right away. They might just continue to divide and be embedded at or beneath the bark for years and then sprout is response to stress. Tree survival after, say, storm injury depends on sprouting from both latent axillary and adventitious buds. My sense is that when I hear an arborist say to make a reduction cut to a node, she means to cut back to what would appear to be a strongly attached branch that is assumed to be derived from an axillary bud. I’m not quibbling with that assumption, at least not yet. I’m just trying to figure out how you folks use these terms.