Genetic, morphological, and spectral characterization of relictual Niobrara River hybrid aspens ( × ).

Premise Of The Study: Aspen groves along the Niobrara River in Nebraska have long been a biogeographic curiosity due to morphological differences from nearby remnant populations. Pleistocene hybridization between and has been proposed, but the nearest populations are currently several hundred kilometers east. We tested the hybrid-origin hypothesis using genetic data and characterized putative hybrids phenotypically.