Dr. Gillespie's research focuses on the systematics and evolution of flowering plants. Her lab uses morphological and molecular methods to explore problems of phylogeny, biogeography, and species circumscription, including the identification and description of new taxa. Research focuses on two large families, grasses (Poaceae) and spurges (Euphorbiaceae), and on the Canadian Arctic flora.

Consaul, L.L., Gillespie, L.J., Waterway, M.J. Evolution and polyploid origins in North American Arctic Puccinellia (Poaceae) based on nuclear ribosomal spacers and chloroplast DNA sequences. American Journal of Botany 27: 324-336, 2010 Gillespie, L.J., Soreng, R.J., Jacobs, S.W.L. Phylogenetic relationships of Australian Poa (Poaceae: Poinae): molecular evidence for two new genera, Saxipoa and Sylvipoa. Australian Journal of Botany 22: 413-436, 2009 Gillespie, L.J., Soreng, R.J., Bull, R., Jacobs, W.L., Refulio-Rodriguez, N.F. Phylogenetic relationships in subtribe Poinae (Poaceae, Poeae) based on nuclear ITS and chloroplast trnT-trnF sequences. Botany 86: 938-967, 2008 Gillespie, L.J. A revision of paleotropical Plukenetia (Euphorbiaceae) including two new species from Madagascar. Systematic Botany 32: 780-802, 2007