Goldman, D.H., R.K. Jansen, C. van den Berg, I.J. Leitch, M.F. Fay, and M.W. Chase. 2004. Molecular and cytological examination of Calopogon (Orchidaceae, Epidendroideae): circumscription, phylogeny, polyploidy and potential hybrid speciation. Amer. J. Bot. 91: 707-723. Google Scholar