https://www.jstor.org/stable/43558218, https://doi.org/10.1016/j.ode.2009.01.001 and https://doi.org/10.1371/journal.pone.0006362 seem to show that both genera sensu Flora Iberica are polyphyletic if you don't accept one broad Cistus, as POWO does. I found this paper which claims phylogenetic work supports separation (https://doi.org/10.1007/s11557-020-01641-0), but the citations are the above which seem to suggest the opposite....