Polyphyly of Limoniastrum (Plumbaginaceae): evidence from DNA sequences ofplastid rbcL, trnL intron and trnL-F intergene spacer

Phylogenetic relationships of Limoniastrum and other genera of subfamily St aticoideae (Plumbaginaceae) were studied using parsimony analysis of the pl astid gene rbcL, the intron of trnL and the intergene spacer of trnL-trnF. Our analysis showed that Limoniastrum was polyphyletic. Limoniastrum ifnien se, in both rbcL and combined data analyses, is sister to Armeria and Psyll iostachys, whereas in the trnL-F (intron and spacer combined) analysis it i s sister to a clade composed of Acantholimon, Dictyolimon and the remaining species of Limoniastrum. In all analyses, the five remaining species of Li moniastrum (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 thr ee groups of Limoniastrum w ere greater than for other well supported genera in the family and, in comb ination with morphological differences and paucity of synapomorphies, led u s to conclude that separate generic status for each of the three clades is warranted. (C) 2000 The Linnean Society of London.