Subtribe Vellinae (Brassiceae, brassicaceae):: a combined analysis of ITS nrDNA sequences and morphological data

Phylogenetic relationships in subtribe Vellinae (Brassiceae. Brassicaceae) were studied using combined parsimony analysis of nucleotide sequences of nuclear ribosomal internal transcribed spacers (ITS) and morphology. Analyses of 17 taxa of Vellinae, Zillinae and Savignyinae, plus two outgroups from Brassicinae, reveal a main clads consisting of Vella plus Boleum. This group is sister to Euzomodendron, to which Carrichtera and Succowia are successive sisters. Although Euzomodendron, a morphologically distinctive genus, is embedded in Vella in the ITS analysis, it is placed as sister to Vella in the combined analysis. Boleum, however, is included in the Vella clade in all cases, and its segregation at the genus rank is inappropriate. Psychine, a genus thought by some authors to be related to Vellinae, is sister to Savignya (Savignyinae). Zillinae and Savignyinae are sister groups in the combined analysis, and the pair is sister to Vellinae. Biogeographical features can be inferred from the combined analysis. The annual representatives of Vellinae (Succowia and Carrichtera) are widespread in the Mediterranean and Irano-Turanian territories. Conversely, the woody taxa are narrow endemics growing in either high-elevation environments or dry, steppe habitats of central and southern Spain, northern Morocco and Algeria. A combination of molecular data, morphology, cytology and biogeographical patterns are used for estimating the general evolutionary patterns of the subtribe. (C) 2000 Annals of Botany Company.