de Lange, P.J.; Heenan, P.B.; Rolfe, J.R. 2011: Checklist of vascular plants recorded from Chathams Islands. Department of Conservation, Wellington Hawke's Bay Conservancy.
L’Héritier de Brutelle, C.-L. 1789: Sertum Anglicum. Didot, Paris.
Mabberley, D.J. 2008: Mabberley's plant book, a portable dictionary of plants, their classification and uses. Edition 3. Cambridge University Press.