Delimiting Species Boundaries in Rosa Sect. Cinnamomeae (Rosaceae) in Eastern North America

Abstract

Abstract This study investigates species boundaries in the polyploid complex of Rosa sect. Cinnamomeae east of the Rocky Mountains. This complex is characterized by extensive intra-specific polymorphism that is the consequence, in part, of hybridization and polyploidy. An objective multivariate approach is employed to delimit species in the complex, which involved cluster and ordination analyses of 25 quantitative morphological characters and of amplified fragment length polymorphisms (AFLPs). Because polyploid individuals blurred species boundaries in the complex, they were discriminated a priori using stomata guard cell lengths in order to investigate species boundaries at each ploidy level separately. Four distinct species were found at the diploid level: R. blanda – R. woodsii, R. foliolosa, R. nitida and R. palustris. According to the morphological and molecular data, R. blanda and R. woodsii are indistinguishable and should be considered as a single species. Three species were identified at the poly...