Phylogeny and Phylogenetic Taxonomy of Dipsacales, with Special Reference to Sinadoxa and Tetradoxa (adoxaceae)

To further clarify phylogenetic relationships within Dipsacales,we analyzed new and previously published rbcL sequences, alone and in combination with morphological data. We also examined relationships within Adoxaceae using rbcL and nuclear ribosomal internal transcribed spacer (ITS) sequences. We conclude from these analyses that Dipsacales comprise two major lineages:Adoxaceae and Caprifoliaceae (sensu Judd et al.,1994), which both contain elements of traditional Caprifoliaceae. Within Adoxaceae, the following relationships are strongly supported: (Viburnum (Sambucus (Sinadoxa (Tetradoxa, Adoxa)))). Combined analyses of C ap ri foliaceae yield the fo l l ow i n g : ( C ap ri folieae (Diervilleae (Linnaeeae (Morinaceae (Dipsacaceae (Triplostegia, Valerianaceae)))))). On the basis of these results we provide phylogenetic definitions for the names of several major clades. Within Adoxaceae, Adoxina refers to the clade including Sinadoxa, Tetradoxa, and Adoxa. This lineage is marked by herbaceous habit, reduction in the number of perianth parts,nectaries of multicellular hairs on the perianth,and bifid stamens. The clade including Morinaceae, Valerianaceae, Triplostegia, and Dipsacaceae is here named Valerina. Probable synapomorphies include herbaceousness,presence of an epicalyx (lost or modified in Valerianaceae), reduced endosperm,and distinctive chemistry, including production of monoterpenoids. The clade containing Valerina plus Linnaeeae we name Linnina. This lineage is distinguished by reduction to four (or fewer) stamens, by abortion of two of the three carpels,and possibly by supernumerary inflorescences bracts.