Matrix representation with parsimony is the most widely used method for supertree reconstruction, due mainly to its ability to deal with incompatible source trees, and its simple and logical mathematical basis. Supertrees have the advantage over consensus methods in that the source trees do not need to contain identical terminal taxa, but only overlap. This makes supertrees a useful and attractive approach to building comprehensive phylogenetic trees, which are indispensable tools for investigating macroevolutionary patterns. Here, we highlight the use of supertrees of two plant lineages. We used the genus-level supertree of grasses (containing almost two-thirds of grass genera) and a family-level supertree of the angiosperms to investigate the influence of various putative key innovations (habit, life form, sex, mode of pollination, mode of dispersal, water resistance, salt tolerance, and habitat preference) on species richness at two different taxonomic levels within the flowering plants. The results suggest that no significant increase in speciation rates could be linked to any of these features in the angiosperms, whereas life form had a significant impact on the number of species at the family level in the grasses.