Various chloroplast DNA data suggested Cornales including two enigmatic monotypic African families Grubbiaceae and Hydrostachyaceae. Forty species representing all major groups of Cornales, including two of three species Grubbia, and four samples representing three of 22 species Hydrostachys, were sequenced for 26S rDNA containing approximate 3300bp in the present study. Phylogenetic analyses using both parsimony and maximum likelihood methods identified Grubbia as the sister of another African genus Curtisia with high bootstrap support congruent with previous findings based on rbcL & matK sequence data. These two genera were allied with the nyssoids in the parsimony analysis, but were recognized as sister of a monophyletic group consisting of nyssoids, matixioids, Cornus, and Alangium in the ML analysis. The four sequences of Hydrostachys were missing approximate 1000 bp near the 5 end. Those four samples of Hydrostachys formed a strongly supported, long-branched monophyletic group sister to the remainder of Cornales. However, this placement was not strongly supported in the parsimony tree. Moreover, this 26S rDNA-based relationship of Hydrostachys differs from that suggested by some earlier analyses of chloroplast genes

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