It is always desirable to have identification keys available for the smallest area one is working in rather than to have to labor through keys covering a larger area, whether a state, region, or nation. My keys for the Black Hills which appeared in 1977 are long out of date. This update has eliminated about 70 species which were reported earlier for the Black Hills but have never been documented with a specimen or reliable literature source. About 180 species have been added to the Black Hills flora since 1977. A high percentage of recent new reports for which specimens could be examined turned out to be misidentified. There are other reports for which I was unable to examine specimens. Some of these may be valid but are not included here. For this update I have chose not to include any descriptions, habitats, nor locations to keep the treatment compact and easily available to all who wish to use it. Detailed descriptions can be found in “Flora of the Great Plains” and in “Flora North America” which is online.