Abstract
Due to broad distribution and great morphological diversity, Festuca ovina and allies, have long been controversial with respect to their taxonomic treatments. Here, their taxonomic treatments are reconsidered using individuals broadly distributed in Japan, based on analyses of morphology (including leaf anatomy), ploidy level, and molecular phylogeny. Molecular analyses based on 70 chloroplast coding sequences (CDS) (52,164 bp in total) from 16 samples distributed from Hokkaido to Kinki District, Honshu, resulted in two robust clades with 100% bootstrap support in the ML tree: one consisting of individuals with sparse leaves, and the other consisting of individuals with dense leaves. Morphologically, the individuals in the latter clade clearly differ from those in the former clade in that at least one nest (none in the former) of old concentric sheaths envelopes four or more new leaf fascicles. As they sometimes grow sympatrically, individuals in the former clade are considered to be F. ruprechtii (lectotypified in this study) and those in the latter clade as F. ovina s.s. The analyses showed that the two species include both diploids and tetraploids and that F. probatovae and F. chiisanensis are synonyms of F. ruprechtii and F. ovina, respectively.
