Figure 4.

Phylogenetic tree of all 64 grass species mapped to: two assemblage groups (for all species except those that could not be attributed to either assemblage); three functional groups of the 39 common species (Eragrostis atrovirens and Schizachyrium exile are not included owing to lack of available sequences); and species endemicity. Functional group C corresponds to the intermediate group in figure 3. (Online version in colour.)