Data from: Specimen-based analysis of morphology and the environment in ecologically dominant grasses: the power of the herbarium
McAllister, Christine A. et al. (2018), Data from: Specimen-based analysis of morphology and the environment in ecologically dominant grasses: the power of the herbarium, Dryad, Dataset, https://doi.org/10.5061/dryad.70f538g
Herbaria contain a cumulative sample of the world’s flora, assembled by thousands of people over several hundred years. Recent advances in computation, DNA sequencing, and image manipulation have allowed us to capitalize on this resource. Using herbarium material, we conducted a species-level analysis of a major clade in the grass tribe Andropogoneae, which includes the dominant species of the world’s grasslands, from the genera Andropogon, Schizachyrium, Hyparrhenia, and other groups. We imaged 188 of the 250 available species of the clade, georeferenced the specimens, and extracted climatic variables for each. Using semiand fully automated image analysis techniques, we extracted spikelet morphological characters and correlated these with environmental variables. We are currently generating chloroplast genome sequences to correct for phylogenetic covariance and here present an analysis of a subset of 81 species, representing the power of this approach. In addition to taxonomic/phylogenetic observations, we find all morphological and ecological characters are homoplasious but variable among clades. For example, sessile spikelet length is positively correlated with awn length when all accessions are considered, but when separated by clade, the relationship is positive for five sub-clades and negative for three others. Macrohair density and pedicel length were negatively correlated with precipitation.
National Science Foundation, Award: DEB-11456884, DEB-1457748