XVI International Botanical Congess

Apiales (Apiaceae and Araliaceae) have traditionally been placed in Rosidae, most often near Cornales. However, recent molecular studies have suggested that Apiales belong to an expanded subclass Asteridae, closely related to Pittosporaceae and four other genera (Griselinia, Toricellia, Melanophylla, and Aralidium). Evaluation of the morphological characters linking Apiales to Rosidae/Cornales and alternatively to Asteridae/Pittosporaceae suggests that traditional systems have employed faulty assumptions regarding character-state polarity. These same assumptions have complicated phylogenetic recontructions between Apiaceae and Araliaceae within the order. Molecular data suggest that Apiales arose from a woody, paleotropical ancestor with simple leaves, bicarpellate flowers with unisexual mating systems and panicles or racemes. All or most of these characters are found among Pittosporaceae (plus the other four genera) and among the basally-branching lineages within Apiales.