The parent-offspring conflict is a paradox wherein parents must balance the investment of limited resources between provisioning their offspring to increase their chances for survival and maturation and reserving resources for their own survival and future reproduction. In many plant lineages parent-offspring conflict is limited to early developmental stages, whereas in bryophytes (mosses, liverworts, hornworts) the offspring sporophyte remains physically attached to and nutritionally dependent on the parental gametophyte throughout its entire life. The sexual system may also influence the parent-offspring conflict with unisexual species having higher levels of conflict in comparison to bisexual species, due to differing levels of genetic relatedness between the offspring and parent. In this study, we test the hypothesis that dioicous moss (species with unisexual gametophytes) will have both (1) larger parental calyptra to decrease offspring resource acquisition and (2) taller offspring seta with larger capsules to increase resource acquisition in comparison to monoicous mosses (species with bisexual gametophytes). We are examining this question in a phylogenetic context using species of Grimmiaceae, Dicranaceae, and Rhabdoweisiaceae. We will present our preliminary findings addressing this hypothesis and discuss their implications for enhancing our understanding of morphological evolution and the parent-offspring conflict in mosses.