The WUSCHEL (WUS) family of transcription factors is well known for its role in stem cell maintenance in seed plants. There are two paralogues of the WUS-RELATED HOMEOBOX 13 (WOX13) gene in the moss Physcomitrella patens, but their function is unknown. Now, on p. 1660, Mitsuyasu Hasebe, Thomas Laux and colleagues investigate the role of the WUX13L paralogues in moss and find that the two genes act redundantly to promote stem cell formation, but via a mechanism that differs from that of seed plants. Using a double knockout of the WOX13L paralogues, the authors show that WOX13L activity is required to initiate the cell growth that is necessary for stem cell formation from detached leaves. Further transcriptome analysis of the double mutant compared with wild-type moss reveals that the WOX13L genes are required for the upregulation of cell wall-loosening genes, revealing a novel function of the WOX gene family.