Flora of North America North of Mexico Volume 28 - Bryophyta, part 2 - includes treatments prepared by 44 authors covering 698 species in 206 genera classified in 48 families. Descriptions for all of the families, genera, and species are provided plus occurrence maps for species are included and 53% of the species are illustrated. Keys are included to aid in the identification of genera in families and species within the genera; an overall key to the 333 genera of mosses known from North America north of Mexico is also included. Volume 28 is the seventeenth volume to be published in the planned 30-volume Flora of North America North of Mexico series.

With the publication of Volume 28, plus the earlier appearance of Volume 27 - Bryophyta, part 1 - in 2007, the treatment of mosses for the Flora area is complete. The currently known moss flora has 1402 species in 333 genera classified in 81 families. For the genera, 17 (5%) are endemic to the Flora area and 273 (19.5%) of the species are endemic with 36 (2.6%) of those considered to be of conservation concern.