All land plants alternate between a multicellular haploid life stage, called the gametophyte, and a multicellular diploid life stage, called the sporophyte. The multicellular gametophyte of plants is distinctly different from the single-celled haploid phase of animal life cycles and is likely conserved from an ancestor which had a multicellular gametophyte and single-celled sporophyte. TALE Homeodomain (TALE-HD) proteins have been implicated in facilitating the transition from the haploid to diploid body plan in land plants via a heterodimerization system between proteins belonging to the two subclasses of TALE-HD: KNOX and BELL. This system has been shown to function in the moss Physcomitrella patens and liverwort Marchantia polymorpha, such that members of both subclasses are necessary for proper sporophyte development. However, in flowering plants the cooperative roles of KNOX and BELL together in the haploid-diploid transition are not as well known. Some KNOX homologs are known to be involved in meristem development and leaf patterning of the sporophyte in ferns and seed plants, suggesting that the function of some of these genes has changed substantially in the evolution of land plants. Ferns, as sister to seed plants, are a key lineage for understanding patterns of evolution across land plants. Molecular approaches are more tractable in the free-living gametophytes of ferns, whereas seed plants have a reduced gametophyte that is usually buried within sporophyte tissue, and is often short-lived. Determining the function of these genes in ferns, particularly in the haploid-diploid transition, will fill gaps in our current understanding of the evolution of TALE-HD proteins across land plants. In this study, we reconstruct the TALE-HD phylogeny  by isolating putative homologs in online databases from select species across land plants, with an emphasis on ferns and lycophytes. We use in situ hybridization in the model fern Ceratopteris richardii to investigate the temporal and  spatial gene expression of the 14 C. richardii TALE-HD homologs  and combine these results with data from transcriptomes, phylogenetic analysis, gene structure and conserved motif analysis, and protein interaction networks to reconstruct the evolution of KNOX and BELL across land plants.