Model organisms are essential tools for biological research. Much of our understanding of plant development, metabolism, and resistance to biotic and abiotic stresses is derived from the genetic model Arabidopsis thaliana. However, plants are a diverse lineage that have evolved suitably diverse mechanisms to adapt and thrive in every terrestrial ecosystem. The moss Physcomitrium patens is an accessible system in that it has a fully sequenced genome, and tools for its genetic manipulation have developed well in the last decade. The tractability of P. patens as a genetic model plant is outstanding, given its haploid-dominant life cycle, clonal propagation, and cellular totipotency. Further, its minimalistic organ structure and developmental patterning greatly simplify characterization of physiological and developmental processes. From this perspective, P. patens has untapped potential. We have developed tools for high-throughput CRISPR/Cas9 mutagenesis, transient expression assays, and allele replacement in P. patens, within the framework of our studies on sphingolipids, which are essential and abundant membrane components. This platform has allowed us to obtain large collections of mutant alleles with a spectrum of phenotype severities, and revealed roles for specific sphingolipid moieties in cytokinesis. Expanding basic plant research to phylodiverse model species will permit new experimental approaches, and will support applied work to understand and improve plant resilience in a changing global climate.