Phylogenetic relationships between Asplenium bourgaei (Boiss.) milde and A-jahandiezii (Litard.) rouy inferred from morphological characters and rbcLsequences

Micromorphological analysis reveals that A. jahandiezii, which occurs as a local endemic taxon in the Grand Canyon du Verdon in southern France, shows substantial differences to A. bourgaei, from the eastern Mediterranean reg ion, in the surface structure of perispores, sporangial indehiscence and th e size of stomatal subsidiary cells. Nucleotide sequences and genetic dista nces (0.9% nucleotide substitutions) of the rbcL gene support the view that both taxa are related but distinct sibling species. Both species form a mo nophyletic group together with Asplenium fontanum and A. majoricum.