1. D. Andrade-Lima, in: Present Day Forest Refuges in Northeastern Brazil, G. T. Prance, ed., Columbia University Press, New York, 1982, p. 245.
2. V. A. Funk, A. Susanna, T. F. Stuessy, and H. Robinson, in: Systematics, Evolution, and Biogeography of Compositae, V. A. Funk, A. Susanna, T. F. Stuessy, and R. J. Bayer (eds.), International association for plant Taxonomy, Vienna, Austria, 2009, p. 171.
3. BFG (The Brazil Flora Group), Rodriguesia, 66, 1085 (2015).
4. D. H. Nicolson, Phytologia, 32, 33 (1975).
5. K. Kubitzki, The Families and Genera of Vascular Plants. Flowering Plants. Eudicots: Asterales, Springer, Berlin, 2007, p. 454.