RELATIONSHIPS OF DROSERACEAE - A CLADISTIC-ANALYSIS OF RBCL SEQUENCE AND MORPHOLOGICAL DATA

Molecular support for the monophyly of Droseraceae and its phylogenetic relationships to other dicot families was investigated using parsimony analysis of nucleotide sequences of the large subunit of ribulose-1,5-bisphosphate carboxylase (rbcL). Analysis of 100 species of plants including families of subclasses Rosidae, Hamamelidae, Dilleniidae, and Caryophyllidae (sensu Cronquist) placed monophyletic Droseraceae in the same clade as Caryophyllidae and Nepenthaceae (Dilleniidae). In a second analysis of 14 species of Droseraceae, 15 caryophyllids, one Nepenthaceae, and three Santalales, a single most-parsimonious tree was found in which Droseraceae are monophyletic, although the position of Drosophyllum as a member of Droseraceae is only weakly supported. The rbcL tree identified four major lineages within genus Drosera: 1) Dionaea; 2) the regia-clade that contains only Drosera regia; 3) the capensis-clade that contains the South African and temperate species outside of Australia; and 4) the peltata-clade that consists of principally Australian endemics. A separate analysis of 14 morphological and phytochemical characters is in general agreement with the rbcL tree except for the placement of Nepenthes, Drosophyllum, and Drosera burmanni. A combined analysis of both data sets places Drosophyllum in a clade with Triphyophyllum (Dioncophyllaceae).