Differences in the centre mid-rib cross-sections within plants of the same species and same accession (seed collected from the same mother plant), but growing under different environmental conditions resulting in a different stage of developmental plant and leaf maturity M, N are Butia paraguayensis plant accession 20060222*M and 20060222*N A, C are Butia yatay. plant accession 20040335*A and 20040335*C. Note the differences in the developmental stage of the plant above and its corresponding anatomy below.