Figure 1.

Phylogeny of the Grass Family.

Relationships based largely on Vicentini et al. (2008) and Christin et al. (2009), showing multiple origins of C₄ photosystems. S. viridis is an NADP-ME subtype C₄ grass that is closely related to the bioenergy feedstock switchgrass (NAD-ME subtype), the grain crop foxtail millet, and the agricultural weed guinea grass (PCK). The C₄ photosynthetic systems in this Setaria/Urochloea/Panicum (SUPa clade, indicated with a yellow star) arose independently from the NADP-ME family members of the Andropononeae (maize, sorghum, sugarcane, and M. x giganteus). Dashed lines show clades with multiple subtypes.