Ph.D., Botany, Duke University, 2005
M.S., Biology, University of North Carolina at Chapel Hill, 1997
B.S., Plant Biology, Cornell University, 1995
Post-doctoral Fellow, Department of Botany, National Museum of Natural History, Smithsonian Institution, 2009–2015

Molecular phylogenetics, evolution, and diversity of flowering plants (especially Florida and the SE United States)
My students and I are currently investigating the molecular phylogenetics of the SE U.S. lineage of Stillingia (Euphorbiaceae) with a view toward clarifying species boundaries and understanding the evolutionary and biogeographic history of the group.

Current courses:

• PCB 3063C — Genetics
• ISC 3120C — Scientific Process
• BSC 1010C — General BiologyI, with Lab
• BOT 3153 — Flora of Southwest Florida

Peer-reviewed articles

• Ernst, M., C.H. Saslis-Lagoudakis, O.M. Grace, N. Nilsson, H.T. Simonsen, J.W. Horn, and N. Rønsted. 2016. Evolutionary prediction of medicinal properties in the genus Euphorbia L. Scientific Reports (Nature) 6: 30531.
• Horn, J.W., Z. Xi, R. Riina, J.A. Peirson, Y. Yang, B.L. Dorsey, P.E. Berry, C.C. Davis, and K.J. Wurdack. 2014. Evolutionary bursts in Euphorbia (Euphorbiaceae) are linked with photosynthetic pathway. Evolution 68: 3485–3504.
• Harris, E.M., J.W. Horn, and W.L. Wagner. 2012. Floral development of the divergent endemic Hawaiian genus Schiedea (Caryophyllaceae), with special emphasis on the floral nectaries. Taxon 61: 576–591.
• Horn, J.W., B.W. van Ee, J.J. Morawetz, R. Riina, V.W. Steinmann, P.E. Berry, and K.J. Wurdack. 2012. Phylogenetics and evolution of major structural characters in the giant genus Euphorbia (Euphorbiaceae). Molecular Phylogenetics and Evolution 63: 305–326.
• Zona, S., P. Davis, L.A.A.H. Gunathilake, J. Prince, and J.W. Horn. 2012. Seeds of Eriocaulaceae of the United States and Canada. Castanea 77: 37–45.
• Moore, M.J., N. Hassan, M.A. Gitzendanner, R.A. Bruenn, M. Croley, A. Vandeventer, J.W. Horn, A. Dhingra, S.F. Brockington, M. Latvis, J. Ramdial, R. Alexandre, A. Piedrahita, Z. Xi, C.C. Davis, P.S. Soltis, and D.S. Soltis. 2011. Phylogenetic analysis of the plastid inverted repeat for 244 species: insights into deeper-level angiosperm relationships from a long, slowly evolving sequence region. International Journal of Plant Sciences 172: 541– 558.
• Horn, J.W. 2009. Phylogenetics of Dilleniaceae using sequence data from four plastid loci (rbcL, infA, rps4, rpl16 intron). International Journal of Plant Sciences 170: 794–813.
• Horn, J.W., J.B. Fisher, P.B. Tomlinson, C.E. Lewis, and K.M. Laubengayer. 2009. Evolution of lamina anatomy in the palm family (Arecaceae). American Journal of Botany 96: 1462–1486.
• Dransfield, J., M. Rakotoarinivo, W.J. Baker, R.P.Bayton, J.B. Fisher, J.W. Horn, B. Leroy, and X. Metz. 2008. A new coryphoid palm genus from Madagascar. Botanical Journal of the Linnean Society 156: 79–91.
• Horn, J.W. 2004. The morphology and relationships of the Sphaerosepalaceae (Malvales). Botanical Journal of the Linnean Society 144: 1–40.

Book

• P.B. Tomlinson, J.W. Horn, and J.B. Fisher. 2011. The anatomy of palms: Arecaceae– Palmae. Oxford University Press. 276 pp.

Book chapters

• Horn, J.W. 2007. Dilleniaceae. In: K. Kubitzki (ed.) The Families and Genera of Vascular Plants Vol. IX. Flowering Plants. Eudicots: Berberidopsidales et al., pp. 132–154. Springer-Verlag, Berlin.