@article{wall_douglas_hoffmann_wentworth_gray_xiang_knaus_hohmann_g._2014, title={Evidence of population bottleneck in Astragalus michauxii (Fabaceae), a narrow endemic of the southeastern United States}, volume={15}, ISSN={1566-0621, 1572-9737}, url={http://link.springer.com/10.1007/s10592-013-0527-2}, DOI={10.1007/s10592-013-0527-2}, number={1}, journal={Conservation Genetics}, publisher={Springer Science and Business Media LLC}, author={Wall, W. A. and Douglas, N. A. and Hoffmann, W. A. and Wentworth, T. R. and Gray, J. B. and Xiang, Q. Y. J. and Knaus, B. K. and Hohmann and G., M.}, year={2014}, month={Feb}, pages={153–164} }
 @article{douglas_wall_xiang_hoffmann_wentworth_gray_hohmann_2011, title={Recent vicariance and the origin of the rare, edaphically specialized Sandhills lily, Lilium pyrophilum (Liliaceae): evidence from phylogenetic and coalescent analyses}, volume={20}, ISSN={["0962-1083"]}, DOI={10.1111/j.1365-294x.2011.05151.x}, abstractNote={Abstract}, number={14}, journal={MOLECULAR ECOLOGY}, author={Douglas, Norman A. and Wall, Wade A. and Xiang, Qiu-Yun and Hoffmann, William A. and Wentworth, Thomas R. and Gray, Janet B. and Hohmann, Matthew G.}, year={2011}, month={Jul}, pages={2901–2915} }
 @article{douglas_spellenberg_2010, title={A new tribal classification of Nyctaginaceae}, volume={59}, number={3}, journal={Taxon}, author={Douglas, N. and Spellenberg, R.}, year={2010}, pages={905–910} }
 @article{wall_douglas_xiang_hoffmann_wentworth_hohmann_2010, title={Evidence for range stasis during the latter Pleistocene for the Atlantic Coastal Plain endemic genus, Pyxidanthera Michaux}, volume={19}, ISSN={["1365-294X"]}, DOI={10.1111/j.1365-294x.2010.04793.x}, abstractNote={The general phylogeographical paradigm for eastern North America (ENA) is that many plant and animal species retreated into southern refugia during the last glacial period, then expanded northward after the last glacial maximum (LGM). However, some taxa of the Gulf and Atlantic Coastal Plain (GACP) demonstrate complex yet recurrent distributional patterns that cannot be explained by this model. For example, eight co‐occurring endemic plant taxa with ranges from New York to South Carolina exhibit a large disjunction separating northern and southern populations by >300 km. Pyxidanthera (Diapensiaceae), a plant genus that exhibits this pattern, consists of two taxa recognized as either species or varieties. We investigated the taxonomy and phylogeography of Pyxidanthera using morphological data, cpDNA sequences, and amplified fragment length polymorphism markers. Morphological characters thought to be important in distinguishing Pyxidanthera barbulata and P. brevifolia demonstrate substantial overlap with no clear discontinuities. Genetic differentiation is minimal and diversity estimates for northern and southern populations of Pxyidanthera are similar, with no decrease in rare alleles in northern populations. In addition, the northern populations harbour several unique cpDNA haplotypes. Pyxidanthera appears to consist of one morphologically variable species that persisted in or near its present range at least through the latter Pleistocene, while the vicariance of the northern and southern populations may be comparatively recent. This work demonstrates that the refugial paradigm is not always appropriate and GACP endemic plants, in particular, may exhibit phylogeographical patterns qualitatively different from those of other ENA plant species.}, number={19}, journal={MOLECULAR ECOLOGY}, author={Wall, Wade A. and Douglas, Norman A. and Xiang, Qiu-Yun and Hoffmann, William A. and Wentworth, Thomas R. and Hohmann, Matthew G.}, year={2010}, month={Oct}, pages={4302–4314} }
 @article{douglas_2008, title={Tripterocalyx carneus (Nyctaginaceae) is self-compatible}, volume={53}, ISSN={["1943-6262"]}, DOI={10.1894/DW-117.1}, abstractNote={Abstract Recent phylogenetic work has demonstrated that the ability of species of the angiosperm family Nyctaginaceae to self-fertilize is evolutionarily labile. However, the potential for further investigation of the evolution of mating systems in the family is limited, because there is no information on reproductive biology for several genera. I performed an experiment on a natural population of Tripterocalyx carneus to determine whether this species is self-compatible. Individual flowers were emasculated, bagged to exclude pollinators, or both. Flowers that were bagged but not emasculated set viable fruit in the majority of cases, which demonstrates that this species is self-compatible.}, number={3}, journal={SOUTHWESTERN NATURALIST}, author={Douglas, Norman A.}, year={2008}, month={Sep}, pages={403–406} }