ALT Bryophyte functional traits are increasingly measured across terrestrial systems to capture the myriad ecological roles contributed by these plants. In this review, the authors compile data from 282 published articles (10005 records spanning 45 years) focusing on functional traits measured in mosses, presenting trends in types of traits measured, taxonomic and geographic breadth of trait coverage, biases in the current literature, and a bryophyte-function index (BFI) to describe completeness of current trait coverage and identify global gaps to focus research efforts. Photos © Des Callaghan