One important question in community ecology is how species interact with one another, and whether these interactions are beneficial or detrimental. Co-flowering of different species within a plant community may increase competition for pollinator resources, but it may also be facilitative and increase pollinator visits and plant fitness. Climate change is also driving shifts in phenology that may change co-flowering patterns. This study aims to determine whether co-flowering in plant communities changes the fitness outcomes for the co-flowering species. These interspecies interactions may also be a factor in community phylogenetic makeup. I will investigate whether co-flowering and associated fitness benefits are related to the phylogenetic makeup of the community. With plots at three different elevations, I will also determine whether the relationship between co-flowering, fitness, and phylogenetic relationships changes between elevations.