Fig 9. Ancestral state reconstruction of leaf morphology and anatomy traits.

Historical analysis of a total of 13 leaf traits, taking all the Oryza species, confirm that small leaf, high vein density, shorter inter-veinal mesophyll area, smaller-sized mesophyll cells, and fewer number of bundle sheath cells surrounding a vein, are the primitive leaf characters in rice. Likewise, a wider inter-veinal mesophyll area, highly-lobed mesophyll cells, and increased bundle sheath cell numbers are advanced characters in cultivated rice leaves. Rhynchoryza subulata was used as an out-group.