As a tree transitions from root to stem along a horizontal, subsurface course in preparation to vertical, above ground alignment, cell and tissue differentiation occurs. Although a wealth is information is available in regards to this transition process, a wide array of terminology associated with the region where stem and roots transition near the base of the main stem exists. Across the associated academic and industry professions that manage trees in the landscape, more than one common term used to describe the transition area, and may include: root collar, root flare, trunk flare, zone-of-rapid-taper, root-stem transition zone, buttress roots and others.  It is obvious that various authors and publications refer to this area by differing terminology and thus may be confusing or misleading to researchers and practitioners investigating the area or prescribing management protocols for the area in question. 

The purpose of this poster presentation is to 1) provide a brief visual overview of associated tree anatomy and physiology of the region, 2) list and cite associated terminology used to describe the region, and 3) gather input for accepted nomenclature for future reference.