Multiple complementary studies clarify which co-occurring congener presents the greatest hybridization threat to a rare Texas endemic wildflower (Hibiscus dasycalyx: Malvaceae)


  • Melody P. Sain Department of Biology and Center for Environment, Biodiversity, and Conservation, University of Texas at Tyler
  • Julia Norrell-Tober Department of Biology and Center for Environment, Biodiversity, and Conservation, University of Texas at Tyler
  • Katherine Barthel Department of Biology and Center for Environment, Biodiversity, and Conservation, University of Texas at Tyler
  • Megan Seawright Department of Biology and Center for Environment, Biodiversity, and Conservation, University of Texas at Tyler
  • Alyssa Blanton Department of Biology and Center for Environment, Biodiversity, and Conservation, University of Texas at Tyler
  • Kate L. Hertweck Department of Biology and Center for Environment, Biodiversity, and Conservation, University of Texas at Tyler
  • John S. Placyk, Jr. Department of Biology and Center for Environment, Biodiversity, and Conservation, University of Texas at Tyler
  • Randall Small Department of Ecology & Evolutionary Biology, University of Tennessee-Knoxville
  • Lance R. Williams Department of Biology and Center for Environment, Biodiversity, and Conservation, University of Texas at Tyler
  • Marsha G. Williams Department of Biology and Center for Environment, Biodiversity, and Conservation, University of Texas at Tyler
  • Joshua A. Banta Department of Biology and Center for Environment, Biodiversity, and Conservation, University of Texas at Tyler



Hibiscus, Ecological Niche Modeling, Conservation, Phylogenetics, Phylogenomics, RADseq, nextRAD, SNPs, Population Genetics, STRUCTURE, GRANULE-BOUND STARCH SYNTHASE


The Neches River Rose Mallow (Hibiscus dasycalyx) is a rare wildflower endemic to Texas that is federally protected in the U.S.A. While previous work suggests that H. dasycalyx may be hybridizing with its widespread congeners, the Halberd-leaved Rose Mallow (H. laevis) and the Woolly Rose Mallow (H. moscheutos), this has not been studied in detail. We evaluated the relative threats to H. dasycalyx posed by hybridization with H. laevis and H. moscheutos by 1) examining their relatedness to one another via modern phylogenomic methods, 2) examining the species’ ecological (dis)similarities to one another using ecological niche modeling, and 3) looking for genomic evidence of hybridization among the three species. Our results suggest that H. dasycalyx is very closely related and ecologically similar to H. laevis, and suggest that H. laevis is interbreeding with H. dasycalyx in the wild. Conversely, H. moscheutos appears to be more distantly related to H. dasycalyx and more ecologically dissimilar, and the two are most likely not hybridizing. For these reasons, we believe that H. laevis poses a greater threat to H. dasycalyx than H. moscheutos. We offer some hypotheses as to why H. dasycalyx and H. laevis are coming into secondary contact where hybridization can occur.


Adkins, R.M., A.H. Walton, & R.L. Honeycutt. 2003. Higher-level systematics of rodents and divergence time estimates based on two congruent nuclear genes. Molec. Phylogen. Evol. 26:409–420.
Aiello-Lammens, M.E., R.A. Boria, A. Radosavljevic, B. Vilela, & R.P. Anderson. 2015. spThin: An R package for spatial thinning of species occurrence records for use in ecological niche models. Ecography 38:541–545.
Allendorf, F.W., R.F. Leary, P. Spruell, & J.K. Wenburg. 2001. The problems with hybrids: Setting conservation guidelines. Trends Ecol. Evol. 16:613–622.
Andrews, K.R., J.M. Good, M.R. Miller, G. Luikart, & P.A. Hohenlohe. 2016. Harnessing the power of RADseq for ecological and evolutionary genomics. Nat. Rev. Genet. 17:81–92.
Angelis, K. & M. Dos Reis. 2015. The impact of ancestral population size and incomplete lineage sorting on Bayesian estimation of species divergence times. Curr. Zool. 61:874–885.
Baird, N.A., P.D. Etter, T.S. Atwood, M.C. Currey, A.L. Shiver, Z.A. Lewis, E.U. Selker, W.A. Cresko, & E.A. Johnson. 2008. Rapid SNP discovery and genetic mapping using sequenced RAD markers. PLoS ONE 3:e3376.
Bakker, V.J., J.K. Baum, J.F. Brodie, A.K. Salomon, B.G. Dickson, H.K. Gibbs, O.P. Jensen, & P.B. McIntyre. 2010. The changing landscape of conservation science funding in the United States. Conserv. Lett. 3:435–444.
Balding, M. & K.J.H. Williams. 2016. Plant blindness and the implications for plant conservation. Conserv. Biol. 30:1192–1199.
Banta, J.A. 2020. Hibiscus nextRAD-Seq Conservation Genomics, Dryad, Dataset. Accessed 6 November 2020.
Bentley, D.R., et al. 2008. Accurate whole human genome sequencing using reversible terminator chemistry. Nature 456:53–59.
Berger, S.A. & A. Stamatakis. 2010. Accuracy of morphology-based phylogenetic fossil placement under Maximum Likelihood. In: ACS/IEEE International Conference on Computer Systems and Applications - AICCSA 2010 Pp.1–9.
Berger, S.A., A. Stamatakis, & R. Lücking. 2011. Morphology-based phylogenetic binning of the lichen genera Graphis and Allographa (Ascomycota: Graphidaceae) using molecular site weight calibration. Taxon 60:1450–1457.
Blake, S.F. 1958. Two species of Hibiscus from Texas. J. Wash. Acad. Sci. 48:277–280.
Blanchard, O.J. 1976. A revision of species segregated from Hibiscus sect. Trionum (Medicus) de Candolle sensu lato (Malvaceae).
Blanco-Bercial, L. & A. Bucklin. 2016. New view of population genetics of zooplankton: RAD-seq analysis reveals population structure of the North Atlantic planktonic copepod Centropages typicus. Molec. Ecol. 25:1566–80.
Bryant, D., R. Bouckaert, J. Felsenstein, N.A. Rosenberg, & A. Roy Choudhury. 2012. Inferring species trees directly from biallelic genetic markers: Bypassing gene trees in a full coalescent analysis. Molec. Biol. Evol. 29:1917–32.
Chadès, I., E. McDonald-Madden, M.A. McCarthy, B. Wintle, M. Linkie, & H.P. Possingham. 2008. When to stop managing or surveying cryptic threatened species. Proc. Natl. Acad. Sci. U.S.A. 105:13936–13940.
Charlesworth, B., C. Bartolome, & V. Noel. 2005. The detection of shared and ancestral polymorphisms. Genet. Res. 86:149–157.
Committee on the Status of Endangered Wildlife in Canada. 2004. COSEWIC assessment and update status report on the swamp rose-mallow Hibiscus moscheutos in Canada. Accessed 27 June 27, 2016.
Correll, D.S. & H.B. Correll. 1972. Aquatic and wetland plants of southwestern United States. Environmental Protection Agency, Washington, DC, U.S.A.
Coyne, J.A. & H.A. Orr. 2004. Speciation. Sinauer, Sunderland, MA, U.S.A.
Daco, L., T. Maurice, S. Muller, J. Rossa, & G. Colling. 2019. Genetic status of the endangered plant species Gladiolus palustris in the western part of its distribution area. Conserv. Genet. 20:1339–1354.
DaCosta, J.M., M.J. Miller, J.L. Mortensen, J.M. Reed, R.L. Curry, & M.D. Sorenson. 2019. Phylogenomics clarifies biogeographic and evolutionary history, and conservation status of West Indian tremblers and thrashers (Aves: Mimidae). Molec. Phylogen. Evol. 136:196–205.
Darriba, D., G.L. Taboada, R. Doallo, & D. Posada. 2012. jModelTest 2: More models, new heuristics and parallel computing. Nat Meth 9:772–772.
Davey, J.W., P.A. Hohenlohe, P.D. Etter, J.Q. Boone, J.M. Catchen, & M.L. Blaxter. 2011. Genome-wide genetic marker discovery and genotyping using next-generation sequencing. Nat. Rev. Genet. 12:499–510.
Deli?, T., P. Trontelj, M. Rendoš, & C. Fišer. 2017. The importance of naming cryptic species and the conservation of endemic subterranean amphipods. Sci. Rep. 7:3391.
Drummond, A.J. & A. Rambaut. 2007. BEAST: Bayesian evolutionary analysis by sampling trees. BMC Evol. Biol. 7.
Edwards, S.V., Z. Xi, A. Janke, B.C. Faircloth, J.E. McCormack, T.C. Glenn, B. Zhong, S. Wu, E.M. Lemmon, A.R. Lemmon, A.D. Leaché, L. Liu, & C.C. Davis. 2016. Implementing and testing the multispecies coalescent model: A valuable paradigm for phylogenomics. Molec. Phylogen. Evol. 94:447–462.
Elith, J. 2002. Quantitative methods for modeling species habitat: Comparative performance and an application to Australian plants. In: S. Ferson & M. Burgman, eds. Quantitative methods for conservation biology Springer, New York, U.S.A. Pp. 39–58.
Evans, R.C., L.A. Alice, C.S. Campbell, E.A. Kellogg, & T.A. Dickinson. 2000. The Granule-Bound Starch Synthase (GBSSI) Gene in the Rosaceae: Multiple loci and phylogenetic utility. Molec Phylogen. Evol. 17(3):388–400.
Excoffier, L. 2003. Analysis of population subdivision. In: D. Balding, M. Bishop, & C. Cannings, eds. Handbook of statistical genetics, 2nd Edition John Wiley and Sons, Ltd., New York, U.S.A. Pp. 713–750.
Excoffier, L. & H.E.L. Lischer. 2010. Arlequin suite ver A new series of programs to perform population genetics analyses under Linux and Windows. Molec. Ecol. Resour. 10:564–567.
Faurby, S., W.L. Eiserhardt, & J.-C. Svenning. 2016. Strong effects of variation in taxonomic opinion on diversification analyses. Methods Ecol. Evol. 7(1):4–13.
Felsenstein, J. 1978. Cases in which parsimony or compatibility methods will be positively misleading. Syst. Zool. 27:401–410.
Felsenstein, J. 1981. Evolutionary trees from DNA sequences: A maximum likelihood approach. J. Molec. Evol. 17:368–76.
Fitzpatrick, B.M., M.E. Ryan, J.R. Johnson, J. Corush, & E.T. Carter. 2015. Hybridization and the species problem in conservation. Curr. Zool. 61:206–216.
Fryxell, P.A. 1988. Malvaceae of Mexico. Syst. Bot. Monogr. 25:1–522.
Galaverni, M., R. Caniglia, L. Pagani, E. Fabbri, A. Boattini, & E. Randi. 2017. Disentangling timing of admixture, patterns of introgression, and phenotypic indicators in a hybridizing wolf population. Molec. Biol. Evol. 34:2324–2339.
Garnett, S.T., & L. Christidis. 2017. Taxonomy anarchy hampers conservation. Nature 546(7656):25–27.
Gow, J.L., C.L. Peichel, & E.B. Taylor. 2007. Ecological selection against hybrids in natural populations of sympatric threespine sticklebacks. J. Evol. Biol. 20:2173–2180.
Guindon, S., J.-F. Dufayard, V. Lefort, M. Anisimova, W. Hordijk, & O. Gascuel. 2010. New algorithms and methods to estimate maximum-likelihood phylogenies: Assessing the performance of PhyML 3.0. Syst. Biol. 59:307–321.
Heled, J. & A.J. Drummond. 2010. Bayesian inference of species trees from multilocus data. Molec. Biol. Evol. 27:570–580.
Hendry, A.P., P. Nosil, & L.H. Rieseberg. 2007. The speed of ecological speciation. Funct. Ecol. 21:455–464.
Hernandez, P.A., C.H. Graham, L.L. Master, & D.L. Albert. 2006. The effect of sample size and species characteristics on performance of different species distribution modeling methods. Ecography 29:773–785.
Hill, W.G. 2012. Quantitative genetics in the genomics era. Curr. Genomics 13:196–206.
Jiang, X., S.V. Edwards, & L. Liu. 2020. The multispecies coalescent model outperforms concatenation across diverse phylogenomic data sets. Syst. Biol. 69:795–812.
Katolikova, M., V. Khaitov, R. Vainola, M. Gantsevich, & P. Strelkov. 2016. Genetic, ecological and morphological distinctness of the blue mussels Mytilus Trossulus Gould and M. Edulis L. in the White Sea. PLoS ONE 11(4):e0152963.
Kearns, A.M., M. Restani, I. Szabo, A. Schroder-Nielsen, J.A. Kim, H.M. Richardson, J.M. Marzluff, R.C. Fleischer, A. Johnsen, & K.E. Omland. 2018. Genomic evidence of speciation reversal in ravens. Nat. Commun. 9:906.
Keeland, B.D. & P.J. Young. 1997. Long-term growth trends of baldcypress (Taxodium distichum (L.) Rich) at Caddo Lake, Texas. Wetlands 17:559–566.
Klips, R.A. 1995. Genetic affinity of the rare eastern Texas endemic Hibiscus dasycalyx (Malvaceae). Amer. J. Bot. 82:1463–1472.
Kubatko, L.S. & J.H. Degnan. 2007. Inconsistency of phylogenetic estimates from concatenated data under coalescence. Syst. Biol. 56:17–24.
Laikre, L., M.K. Schwartz, R.S. Waples, & N. Ryman. 2010. Compromising genetic diversity in the wild: Unmonitored large-scale release of plants and animals. Trends Ecol. Evol. 25:520–529.
Lamer, J.T., G.G. Sass, J.Q. Boone, Z.H. Arbieva, S.J. Green, & J.M. Epifanio. 2014. Restriction site-associated DNA sequencing generates high-quality single nucleotide polymorphisms for assessing hybridization between bighead and silver carp in the United States and China. Molec. Ecol. Resour. 14:79–86.
Langmead, B., C. Trapnell, M. Pop, & S.L. Salzberg. 2009. Ultrafast and memory-efficient alignment of short DNA sequences to the human genome. Genome Biol. 10:R25.
Larcombe, M.J., R.E. Vaillancourt, R.C. Jones, & B.M. Potts. 2014. Assessing a Bayesian approach for detecting exotic hybrids between plantation and native eucalypts. Int. J. For. Res. 2014:650202.
Leaché, A.D., R.B. Harris, B. Rannala, & Z. Yang. 2014. The influence of gene flow on species tree estimation: A simulation study. Syst. Biol. 63:17–30.
Lecointre, G. & P. Deleporte. 2005. Total evidence requires exclusion of phylogenetically misleading data. Zool. Scr. 34:101–117.
Li, H., B. Handsaker, A. Wysoker, T. Fennell, J. Ruan, N. Homer, G. Marth, G. Abecasis, R. Durbin, & 1000 Genome Project Data Processing Subgroup. 2009. The Sequence Alignment/Map format and SAMtools. Bioinformatics 25:2078–2079.
Liu, L., C. Anderson, D. Pearl, & S.V. Edwards. 2019. Modern phylogenomics: Building phylogenetic trees using the Multispecies Coalescent Model. In: M. Anisimova, ed. Evolutionary genomics: Statistical and computational methods. Springer, New York, NY, U.S.A. Pp. 211–239.
Liu, L. & D.K. Pearl. 2007. Species trees from gene trees: Reconstructing bayesian posterior distributions of a species phylogeny using estimated gene tree distributions. Syst. Biol. 56:504–514.
Losos, J.B. 2008. Phylogenetic niche conservatism, phylogenetic signal and the relationship between phylogenetic relatedness and ecological similarity among species. Ecol. Lett. 11:995–1003.
Maddison, W.P. & D.R. Maddison. 2014. Mesquite: A modular system for evolutionary analysis. Version 3.01
Matute, D.R., I.A. Butler, D.A. Turissini, & J.A. Coyne. 2010. A test of the snowball theory for the rate of evolution of hybrid incompatibilities. Science 329:1518–1521.
Mendoza, E.A. 2004. Genetic diversity within Hibiscus dasycalyx, Hibiscus laevis and Hibiscus moscheutos utilizing ISSR techniques.
Mirarab, S., M.S. Bayzid, & T. Warnow. 2016. Evaluating summary methods for multilocus species tree estimation in the presence of incomplete lineage sorting. Syst. Biol. 65:366–380.
Morrone, J.J. & J.V. Crisci. 1995. Historical biogeography: Introduction to methods. Ann. Rev. Ecol. Syst. 26:373–401.
Muller, H.J. 1942. Isolating mechanisms, evolution, and temperature. Biol. Symp. 6:71.
Nabhan, A.R., & I.N. Sarkar. 2012. The impact of taxon sampling on phylogenetic inference: A review of two decades of controversy. Brief. Bioinform. 13(1):122–34.
Nascimento, F.F., M.D. Reis, & Z. Yang. 2017. A niologist’s guide to Bayesian phylogenetic analysis. Nat. Ecol. Evol. 1(10):1446–54.
Niu, T., Z.S. Qin, X. Xu, & J.S. Liu. 2002. Bayesian haplotype inference for multiple linked single-nucleotide polymorphisms. Amer. J. Hum. Genet. 70:157–169.
Nordal, I. & B. Stedje. 2005. Paraphyletic taxa should be accepted. Taxon 54:5.
Nosil, P., B.J. Crespi, & C.P. Sandoval. 2003. Reproductive isolation driven by the combined effects of ecological adaptation and reinforcement. Proc. R. Soc. Lond. Ser. B-Biol. Sci. 270:1911–1918.
Oregon Department of Transportation. 2005. ODOT erosion control manual: Guidelines for developing and implementing erosion and sediment controls. Appendix B. Prepared by Harza Engineering Company and ODOT Geo/Environmental Section. Accessed 17 October, 2020.
Padial, J.M., A. Miralles, I. De la Riva, & M. Vences. 2010. The integrative future of taxonomy. Front. Zool. 7(1):16.
Pante, E., C. Schoelinck, & N. Puillandre. 2015. From integrative taxonomy to species description: One step beyond. Syst. Biol. 64(1):152–60.
Pearson, R.G., C.J. Raxworthy, M. Nakamura, & A.T. Peterson. 2007. Predicting species distributions from small numbers of occurrence records: A test case using cryptic geckos in Madagascar. J. Biogeogr. 34:102–117.
Philippe, H., H. Brinkmann, D.V. Lavrov, D.T.J. Littlewood, M. Manuel, G. Wörheide, & D. Baurain. 2011. Resolving difficult phylogenetic questions: Why more sequences are not enough. PLOS Biol. 9:e1000602.
Phillips, S.J. 2017. A brief tutorial on Maxent. Available from url: Accessed 18 September, 2019.
Phillips, S.J., R.P. Anderson, & R.E. Schapire. 2006. Maximum entropy modeling of species geographic distributions. Ecol. Model. 190:231–259.
Phillips, S.J. & M. Dudik. 2008. Modeling of species distributions with Maxent: New extensions and a comprehensive evaluation. Ecography 31:161–175.
Pollard, D.A., V.N. Iyer, A.M. Moses, & M.B. Eisen. 2006. Widespread discordance of gene trees with species tree in Drosophila: Evidence for incomplete lineage sorting. PLOS Genet. 2:e173.
Porras-Hurtado, L., Y. Ruiz, C. Santos, C. Phillips, A. Carracedo, & M.V. Lareu. 2013. An overview of STRUCTURE: Applications, parameter settings, and supporting software. Front. Genet. 4:98.
Pritchard, J.K., M. Stephens, N.A. Rosenberg, & P. Donnelly. 2000. Association mapping in structured populations. Amer. J. Hum. Genet. 67:170–181.
R Core Team. 2020. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria.
Rannala, B., S. Edwards, A. Leache, & Z. Yang. 2020. The multi-species coalescent model and species tree inference. Phylogenetics in the Genomic Era. 3–3.
Raxworthy, C.J., C.M. Ingram, N. Rabibisoa, & R.G. Pearson. 2007. Applications of ecological niche modeling for species delimitation: A review and empirical evaluation using Day Geckos (Phelsuma) from Madagascar. Syst. Biol. 56:907–923.
Rhymer, J.M. & D. Simberloff. 1996. Extinction by hybridization and introgression. Ann. Rev. Ecol. Syst. 27:83–109.
Rieseberg, L.H. & L. Brouillet. 1994. Are many plant species paraphyletic? Taxon 43:21–32.
Rodríguez, A., J.D. Burgon, M. Lyra, I. Irisarri, D. Baurain, L. Blaustein, B. Göçmen, S. Künzel, B.K. Mable, A.W. Nolte, M. Veith, S. Steinfartz, K.R. Elmer, H. Philippe, & M. Vences. 2017. Inferring the shallow phylogeny of true salamanders (Salamandra) by multiple phylogenomic approaches. Molec. Phylogen. Evol. 115:16–26.
Roff, D.A. 2007. A centennial celebration for quantitative genetics. Evolution 61:1017–1032.
Rogers, J. & R.A. Gibbs. 2014. Comparative primate genomics: Emerging patterns of genome content and dynamics. Nat. Rev. Genet. 15:347–359.
Rojas, M. 1992. The species problem and conservation: What are we protecting? Conserv. Biol. 6(2):170–78.
Rubin, B.E.R., R.H. Ree, & C.S. Moreau. 2012. Inferring phylogenies from RAD sequence data. PLoS ONE 7:e33394.
Russello, M.A., M.D. Waterhouse, P.D. Etter, & E.A. Johnson. 2015. From promise to practice: Pairing non-invasive sampling with genomics in conservation. PeerJ 3:e1106–e1106.
Sanz, N., R.M. Araguas, R. Fernández, M. Vera, & J.-L. García-Marín. 2009. Efficiency of markers and methods for detecting hybrids and introgression in stocked populations. Conserv. Genet. 10:225–236.
Schluter, D. 2009. Evidence for ecological speciation and its alternative. Science 323:737–741.
Scott, S.E. 1997. The horticultural treatment and introduction of a rare wetland plant: Neches River rose mallow (Hibiscus dasycalyx). Master’s thesis, Stephen F. Austin State University, Nacogdoches, Texas, U.S.A.
Shi, W., Q. Ayub, M. Vermeulen, R. Shao, S. Zuniga, K. van der Gaag, P. de Knijff, M. Kayser, Y. Xue, & C. Tyler-Smith. 2010. A worldwide survey of human male demographic history based on Y-SNP and Y-STR data from the HGDP-CEPH populations. Molec. Biol. Evol. 27:385–393.
Simmons, M.P. & J. Gatesy. 2015. Coalescence vs. concatenation: Sophisticated analyses vs. first principles applied to rooting the angiosperms. Molec. Phylogen. Evol. 91:98–122.
Small, R.L. 2004. Phylogeny of Hibiscus sect. Muenchhusia (Malvaceae) based on chloroplast rpL16 and ndhF, and nuclear ITS and GBSSI sequences. Syst. Bot. 29:385–392.
Smith, S.A., M.J. Moore, J.W. Brown, & Y. Yang. 2015. Analysis of phylogenomic datasets reveals conflict, concordance, and gene duplications with examples from animals and plants. BMC Evol. Biol. 15(1):150.
Sokal, R.R. & F.J. Rohlf. 1995. Biometry: The principles and practice of statistics in biological research. 2nd ed.
Soulé, M.E. 1985. What is conservation biology? Bioscience 35:727–734.
Stamatakis, A. 2006. RAxML-VI-HPC: Maximum likelihood-based phylogenetic analyses with thousands of taxa and mixed models. Bioinformatics 22.
Stephens, M., N.J. Smith, & P. Donnelly. 2001. A new statistical method for haplotype reconstruction from population data. Amer. J. Hum. Genet. 68:978–89.
Steppan, S.J., R.M. Adkins, & J. Anderson. 2004. Phylogeny and divergence-date estimates of rapid radiations in muroid rodents based on multiple nuclear genes. Syst. Biol. 53:533–553.
Texas Land Conservancy. 2015. Hibiscus Preserve: Houston County. Accessed 17 October, 2020.
Texas Parks & Wildlife Department. n.d. Neches River Rose Mallow. Accessed 17 October, 2020.
Thompson, J.D., D.G. Higgins, & T.J. Gibson. 1994. CLUSTALW: Improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice. Nucleic Acids Res. 22:4673–4680.
Thompson, J.D., S. Lavergne, L. Affre, M. Gaudeul, & M. Debussche. 2005. ecological differentiation of mediterranean endemic plants. Taxon 54:967–976.
Todesco, M., M.A. Pascual, G.L. Owens, K.L. Ostevik, B.T. Moyers, S. Hubner, S.M. Heredia, M.A. Hahn, C. Caseys, D.G. Bock, & L.H. Rieseberg. 2016. Hybridization and extinction. Evol. Appl. 9:892–908.
United States Department of Agriculture, National Resources Conservation Service, & National Soil Survey Center. 1995. State Soil Geographic (STATSG0) Data Base: Data use information. Misc. Publ. No. 1492. Accessed 13 September, 2018.
US Fish & Wildlife Service. 2013. 50 CFR Part 17: Endangered and threatened wildlife and plants; designation of critical habitat for Texas Golden Gladecress and Neches River Rose-Mallow; final rule. Accessed 8 September, 2014.
Usher, A.V., R.J. Whelan, & D.J. Ayre. 2010. Window of opportunity: An episode of recruitment in a Banksia hybrid zone demonstrates continuing hybridization and phenotypic plasticity. Ann. Bot. 105:419–429.
Villarini, G. & J.A. Smith. 2013. Flooding in Texas: Examination of temporal changes and impacts of tropical cyclones. J. Amer. Water Resour. Assoc. 49:825–837.
Vuillaume, B., V. Valette, O. Lepais, F. Grandjean, & M. Breuil. 2015. Genetic evidence of hybridization between the endangered native species iguana delicatissima and the invasive Iguana iguana (Reptilia, Iguanidae) in the Lesser Antilles: Management Implications. PloS One 10:e0127575–e0127575.
Waldron, A., A.O. Mooers, D.C. Miller, N. Nibbelink, D. Redding, T.S. Kuhn, J.T. Roberts, & J.L. Gittleman. 2013. Targeting global conservation funding to limit immediate biodiversity declines. Proc. Natl. Acad. Sci. 110:12144.
Walters, A.D., D. Ford, E.T. Chong, M. Williams, N.B. Ford, L.R. WIlliams, & J.A. Banta. 2017. High-resolution ecological niche modeling of threatened freshwater mussels in east Texas, USA. Aquat. Conserv. Mar. Freshw. Ecosyst. Press.
Wang, J. 2017. The computer program STRUCTURE for assigning individuals to populations: Easy to use but easier to misuse. Molec. Ecol. Resour. 17:981–990.
Warnock, M.J. 1995. Status report on Hibiscus dasycalyx. US Fish & Wildlife Service, Albuquerque, NM, U.S.A.
Warren, D.L., R.E. Glor, & M. Turelli. 2010. ENMTools: A toolbox for comparative studies of environmental niche models. Ecography 33:607–611.
Warren, D.L., R.E. Glor, & M. Turelli. 2008. Environmental niche equivalency versus conservatism: Quantitative approaches to niche evolution. Evolution 62:2868–2883.
Wielstra, B., T. Burke, R.K. Butlin, A. Avc?, N. Üzüm, E. Bozkurt, K. Olgun, & J.W. Arntzen. 2017. A genomic footprint of hybrid zone movement in crested newts. Evol. Lett. 1:93–101.
Wiens, J.J. & C.H. Graham. 2005. Niche conservatism: Integrating evolution, ecology, and conservation biology. Ann. Rev. Ecol. Evol. Syst. 36:519–539.
Winters, H.F. 1970. Our hardy Hibiscus species as ornamentals. Econ. Bot. 24:155–164.
Wise, D.A. & M.Y. Menzel. 1971. Genetic affinities of the North American species of Hibiscus sect. Trionum. Brittonia 23:425–437.
Wolock, D.M. 1997. STATSGO soil characteristics for the conterminous United States. Open-file report 97-656. Accessed 30 May, 2017.
Wurbs, R.A. & R.A. Ayala. 2014. Reservoir evaporation in Texas, USA. J. Hydrol. 510:1–9.
Yasuda, N., C. Taquet, S. Nagai, M. Fortes, T.-Y. Fan, S. Harii, T. Yoshida, Y. Sito, & K. Nadaoka. 2015. Genetic diversity, paraphyly and incomplete lineage sorting of mtDNA, ITS2 and microsatellite flanking region in closely related Heliopora species (Octocorallia). Molec. Phylogen. Evol. 93:161–171.
Young, A.D. & J.P. Gillung. 2020. Phylogenomics—principles, opportunities and pitfalls of big-data phylogenetics. Syst. Entomol. 45:225–247.
Zemanova, M.A. 2019. Poor implementation of non-invasive sampling in wildlife genetics studies. Rethink. Ecol. 4:119–132.
Zhou, X., X.-X. Shen, C.T. Hittinger, & A. Rokas. 2018. Evaluating fast maximum likelihood-based phylogenetic programs using empirical phylogenomic data sets. Molec. Biol. Evol. 35:486–503.




How to Cite

Sain, M. P. ., Norrell-Tober, J. ., Barthel, K., Seawright, M. ., Blanton, A. ., Hertweck, K. L. ., Placyk, Jr., J. S. ., Small, R. ., Williams, L. R. ., Williams, M. G. ., & Banta, J. A. . (2021). Multiple complementary studies clarify which co-occurring congener presents the greatest hybridization threat to a rare Texas endemic wildflower (Hibiscus dasycalyx: Malvaceae). Journal of the Botanical Research Institute of Texas, 15(1), 283–308.