Heenan, P.B.; de Lange, P.J.; Cameron, E.K.; Parris, B.S. 2008: Checklist of dicotyledons, gymnosperms, and pteridophytes naturalised or casual in New Zealand: additional records 2004–06. New Zealand Journal of Botany 46: 257–283.
Lindley, J. 1821-1826: Collectanea Botanica; or, Figures and Botanical Illustrations of Rare and Curious Exotic Plant. R. & A. Taylor, London.
Mabberley, D.J. 2008: Mabberley's plant book, a portable dictionary of plants, their classification and uses. Edition 3. Cambridge University Press.