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Iridaceae are one of the largest families of Lilianae and probably also among the best studied of monocotyledons. To further evaluate generic, tribal, and subfamilial relationships we have produced four plastid DNA data sets for 57 genera of Iridaceae plus outgroups: rps4, rbcL (both protein-coding genes), the trnL intron, and the trnL-F intergenic spacer. All four matrices produce similar although not identical trees, and we thus analyzed them in a combined analysis, which produced a highly resolved and well-supported topology, in spite of the fact that the partition homogeneity test indicated strong incongruence. In each of the individual trees, some genera or groups of genera are misplaced relative to morphological cladistic studies, but the combined analysis produced a pattern much more similar to these previous ideas of relationships. In the combined tree, all subfamilies were resolved as monophyletic, except Nivenioideae that formed a grade in which Ixioideae were embedded. Achlorophyllous Geosiris (sometimes referred to Geosiridaceae or Burmanniaceae) fell within the nivenioid grade. Most of the tribes were monophyletic, and Isophysis (Tasmanian) was sister to the rest of the family; Diplarrhena (Australian) fell in a well-supported position as sister to Irideae/Sisyrinchieae/Tigridieae/Mariceae (i.e., Iridoideae); Bobartia of Sisyrinchieae is supported as a member of Irideae. The paraphyly of Nivenioideae is suspicious due to extremely high levels of sequence divergence, and when they were constrained to be monophyletic the resulting trees were only slightly less parsimonious (

Phylogenetic relationships of Limoniastrum and other genera of subfamily Staticoideae (Plumbaginaceae) were studied using parsimony analysis of the plastid gene rbc L, the intron of trn L and the intergene spacer of trnL - trn F. Our analysis showed that Limoniastrum was polyphyletic.Limoniastrum ifniense , in both rbc L and combined data analyses, is sister to Armeria andPsylliostachys , whereas in the trn L-F (intron and spacer combined) analysis it is sister to a clade composed ofAcantholimon , Dictyolimon and the remaining species of Limoniastrum. In all analyses, the five remaining species of Limoniastrum (excluding Limoniastrum ifniense) formed a clade with two groups of species L. monopetalum+L. guyonianum and those sometimes considered as the segregate genus Bubania ( L. feei, L. weygandiorum and L. rechingeri). Levels of sequence divergence among these three groups of Limoniastrum were greater than for other well supported genera in the family and, in combination with morphological differences and paucity of synapomorphies, led us to conclude that separate generic status for each of the three clades is warranted.