St. Louis F ew floristic inventories of bryophytes have been made in the United States, primarily because of lack of trained personnel. The paucity of manuals in the western United States is especially critical because of the uniqueness of the western North American flora. The moss Leucolepis acanthoneuron . Although this flora is unreliable for the mosses in the midcontinent, it covers the mosses from the eastern United States and the west coast regions well. The eastern forest region is the strongest area for moss floristics in the United States.
Most states there have recent checklists of mosses.
The distribution of mosses in other parts of the country is not as well known. The Southwest is also one of the least known U.S. areas. It has great diversity of habitats including mountains, grasslands, and desert habitats. The Great Plains is reasonably well covered with checklists and two regional floras for all of the midcontinent. Moss diversity in this region is low, and many of the mosses are members of the eastern moss flora.