References

For Houstonia

Church, S.A. 2003. Molecular phylogenetics of Houstonia (Rubiaceae): descending aneuploidy and breeding system evolution in the radiation of the lineage across North America. Molec. Phylogen. Evol. 27: 223-238. Google Scholar

Church, S.A., and D.R. Taylor. 2005. Speciation and hybridization among Houstonia (Rubiaceae) species: the influence of polyploidy on reticulate evolution. Am. J. Bot. 92: 1372-1380. Google Scholar

Glennon, K.L., and S.A. Church. 2015. Gene flow contributes to genetic diversity of tetraploid populations of the North American plant genus Houstonia (Rubiaceae). Rhodora 117: 41-66. Google Scholar

Guo, X., R.-J. Wang, M.P. Simmons, P. P.-H. But, and J. Yu. 2013. Phylogeny of the Asian Hedyotis-Oldenlandia complex (Spermacoceae, Rubiaceae): evidence for high levels of polyphyly and the parallel evolution of dilpophragmous capsules. Molecular Phylogenetics and Evolution 67: 110-122. Google Scholar

Pease, A.S., and A.H. Moore. 1907. An alpine variety of Houstonia caerulea. Rhodora 9: 209-210. Google Scholar

Rogers, G.K. 1987. The genera of Cinchonoideae (Rubiaceae) in the southeastern United States. J. Arnold Arb. 68: 137-183. Google Scholar

Rogers, G.K. 2005. The genera of Rubiaceae in the southeastern United States, part II. Subfamily Rubioideae, and subfamily Cinchonoideae revisited (Chiococca, Erithalis, and Guettarda). Harvard Papers in Botany 10: 1-45. Google Scholar

Shanks, H.L. 2015. Molecular phylogeny of the genus Houstonia and allies in Rubiaceae. M.S. thesis, Biological Sciences, Old Dominion University. DOI: 10.25777/th0k-rv14 https://digitalcommons.odu.edu/biology_etds/3 Google Scholar

Terrell, E.E. 1959. A revision of the Houstonia purpurea group (Rubiaceae). Rhodora 61: 157-181, 188-207. Google Scholar

Terrell, E.E. 1986. Taxonomic and nomenclatural notes on Houstonia nigricans (Rubiaceae). Sida 11: 471-481. Google Scholar

Terrell, E.E. 1991. Overview and annotated list of North American species of Hedyotis, Houstonia, Oldenlandia, and related genera. Phytologia 71: 212-243. Google Scholar

Terrell, E.E. 1996. Revision of Houstonia (Rubiaceae-Hedyotidae). Syst. Bot. Monographs 48: 1-118. Google Scholar

Terrell, E.E. 2001. Taxonomy of Stenaria (Rubiaceae: Hedyotitideae), a new genus including Hedyotis nigricans. Sida 19: 591-614. Google Scholar

Terrell, E.E. 2007. Relationships of Houstonia prostrata (Rubiaceae) of Mexico and Arizona and a review of Houstonia subgenera and sections. J. Bot. Res. Inst. Texas 1: 109-119. Google Scholar

Turner, B.L. 1995b. Taxonomic overview of Hedyotis nigricans (Rubiaceae) and closely allied taxa. Phytologia 79: 12-21. [with corrected map: Phytologia 80: 142-143] Google Scholar

Turner, B.L. 1997. Rebuttal to Terrell's taxonomic notes of Turner's treatment of Texan and Mexican Hedyotis. Phytologia 82: 82-85. Google Scholar

Ward, D.B. 2004c. New combinations in the Florida flora II. Novon 14: 365-371. Google Scholar

Wikström, N., S. Neupane, J. Kårehed, T.J. Motley, and B. Bremer. 2013. Phylogeny of Hedyotis L. (Rubiaceae: Spermacoceae): redefining a complex Asian-Pacific assemblage. Taxon 62: 357-374. Google Scholar