1. Carlquist S. Comparative plant anatomy: A guide to taxonomic and evolutionary applications of anatomical data in angiosperms. New York: Rinehart Winston; 1961.
2. Radford AE, Dickison WC, Massey JR, Bell CR. Vascular Plant Systematics. New York: Harper and Row Publishers; 1974.
3. Metcalfe CR. Anatomy of the dicotelydons. 2nd ed. vol. 1: Systematic anatomy of leaf and stem, with a brief history of the subject. Oxford: Oxford Science; 1979.
4. Stuessy TF. Plant taxonomy. New York: Columbia University Press; 1990.
5. Judd WS, Campbell CS, Kellogg EA, Stevens PF, Donoghue MJ. Plant systematics: a phylogenetic approach. 3rd ed. Massachusetts: Sinauer Associates INC.; 2008.