Here I present a cladistically based monograph of a group of closely related mosses known as the Syrrhopodon involutus complex. Monographs remain a critical and indispensable component of systematics, but traditional monographic practices require some revisions if modern monographs are to truly reflect and incorporate phylogenetic understanding. I summarize the methods used to address issues relating to sampling and the formation of OTUs for this monograph, and emphasize the importance of incorporating morphological character data in a total evidence phylogenetic analysis. In addition to a traditional Linnaean taxonomic treatment, I provide rank-free definitions of the terminal taxa in the S. involutus complex. Following the PhyloCode recommendations for the designation and naming of more inclusive taxa, I present a novel method for naming terminal taxa as least-inclusive clades. This monographic treatment represents a first attempt at applying the PhyloCode at the terminal level in any plant group, and recognizes five distinct taxa in the S. involutus complex, which I have designated with the rank-free clade name Leucophanella: banksii, borneensis, involutus, rufescens, and revolutus.