This is introductory information to provide user information for the NVC Macrogroup Key found at:

This interactive tool was developed by Michael Lee with the Southeastern Flora Team at North Carolina Botanical Garden, University of North Carolina. Suggestions for improvements to the tool can be shared with the Southeastern Flora Team (flora@office.unc.edu) or with the Applications Committee of the NVC Vegetation Panel (veg_panel@programs.esa.org).

This Macrogroup Key is based on USNVC 3.0, the October 2025 version of the U.S. National Vegetation Classification. This tool considers floristic, environmental, and biogeography of macrogroups and component groups, alliances, and associations, and covers the U.S., Canada, and Mexico. The online interface for the key allows the user to select and weight variables to identify macrogroups.

To find macrogroups of interest:

1. Type in the two letter code for your state (or province). The tool accepts only one state at a time.
2. Check the adjacent box if you wish to include adjacent states in the results, which are reflected in lower scoring for macrogroups occurring outside the chosen state.
3. Add an environment search term, if desired, to create a strict search that only includes macrogroups with those exact terms. Example terms include desert, wetland, woodland, succulent scrub, meadow, and other terms that would appear in the naming or concept of the macrogroups themselves. This is also an opportunity to focus the query by physiognomy such as riparian scrub, dwarf shrubland, forest, woodland, etc. Only one term or phrase can be entered, and the tool ignores some characters (e.g., dwarf shrubland and dwarf-shrubland yield the same results).
4. Add a diagnostic species weight between 1 and 10, if desired. For example, if 1 is selected, diagnostic species are weighted the same as any species and will not appear differently in the output.
5. Check the adjacent box if you wish to search on species prevalence. Prevalence is the total number of elements containing the search species within macrogroups, divided by the number of elements tied to that macrogroup. The result is on a scale from 0 to 100.
6. Add one or more desired search species using Latin binomials. These species act as additional criteria for the query along with diagnostic species.
7. Click on ‘Search’ to see results and then on ‘show/edit search’ to modify the search. Click on ‘Clear Form’ at the bottom to begin a new search.

The tool outputs a listing of macrogroups that meet conditions of the query, along with the relative strength of each query variable. The macrogroups can then be sorted based on compiled scores to contrast their level of alignment with the conditions stipulated by the user. Click on the macrogroup names to view macrogroup descriptions at NatureServe Explorer.