PHYLOGENETIC-RELATIONSHIPS OF CORNUS-L SENSU-LATO AND PUTATIVE RELATIVES INFERRED FROM RBCL SEQUENCE DATA

A parsimony analysis of 46 rbcL sequences was performed to evaluate relationships among Cornus and putative relatives, as well as among subgroups within Cornus. Our results indicate that Alangium, nyssoids (Nyssa, Davidia, and Camptotheca), mastixioids (Diplopanax and Mastixia), Curtisia, and genera of Hydrangeaceae are the closest relatives of Cornus. These taxa, plus Cornus, constitute a ''cornaceous clade,'' which differs from all previously proposed Cornus alliances. Within this cornaceous clade, four major fineages were identified; (i) Cornus-Alangium, (ii) nyssoids-mastixioids, (iii) Curtisia, and (iv) hydrangeoids. The relationships among the four major lineages within the cornaceous clade remain unresolved. Sequence data from rbcL also reveal that Corokia, Helwingia, Aucuba, Garrya, and Griselinia, previously placed in Cornaceae by some authors, are only distantly related to Cornus and other members of the cornaceous clade. Four major fineages were identified within Cornus by rbcL sequence data, but relationships among these groups are incompletely resolved.