Data from: Molecular and Morphological Variation among Populations of Pediomelum tenuiflorum (Pursh) A.N. Egan (Fabaceae) in Nebraska, USA

Individuals of Pediomelum tenuiflorum, “wild alfalfa”, from disjunct
populations in Nebraska vary extensively in their overall gestalt. Those
in the western and central part of the state have a very slender growth
habit, with thin stems and few, small flowers; whereas, those in the
southeast have a very robust growth habit with heavy-looking stems and
many tightly clustered flowers. For nearly 200 years, taxonomists have
alternated between splitting P. tenuiflorum into two species, with the
many-flowered morphotype named P. floribundum, and lumping all the
morphological variants into one species as they are now. In this study, we
investigated morphological and molecular characters that could be used to
clarify taxonomic classifications of these morphotypes. We measured 10
morphological characters on 51 specimens and sequenced nearly 300,000
nucleotide characters on the Illumina platform from three cellular genomes
in seven samples of Pediomelum plus an outgroup taxon. Results revealed
six significantly different morphological characters but ambiguous
evolutionary histories of the plastid and mitochondrial genomes in P.
tenuiflorum. Our complete plastid genomes and genes and noncoding regions
of the mitochondrial genome may be used as a foundation for studying the
evolutionary histories of these genomes. Additionally, we identified seven
highly variable genomic regions in the chloroplast genome upon which a
molecular phylogenetic investigation on an expanded set of samples from
across the species’ geographic distribution can be conducted to further
define the taxonomic placements of P. tenuiflorum and P. floribundum.