Morphological and molecular phylogenetic analyses of geranium yesoense (Geraniaceae) in Japan

Abstract

Geranium yesoense (Geraniaceae) includes several varieties that are mainly discriminated by two morphological features, namely, the degree of leaf incision and the density of spreading hairs on the sepals, but these features have never been objectively quantified. To clarify whether these features can truly discriminate varieties, we analyzed leaf shape and sepal pubescence, and conducted a molecular phylogenetic analysis using nuclear and chloroplast DNA. Our morphological analyses showed some trends in leaf morphology and density of hairs, but failed to identify any groupings that could be clearly distinguished on the basis of these features. Our molecular analysis recognized G. yesoense as a distinct taxon, but did not support the existence of subgroups within the species. We conclude that G. yesoense must be treated as a single taxon with some tendency toward morphological variation depending on locality and habitat.