• Acheson, R. M., Jenkins, C. L., Harper, J. L. & McNaughton, I. H. (1962). Floral pigments in Papaver and their significance in the systematics of the genus. New Phytol., 61, 256.
  • Allan, H. H. (1961). Flora of New Zealand. Government printer, New Zealand .
  • Anderson, E. (1949). Introgressive Hybridisation. Wiley, New York .
  • Geismann, T. A. (1955). Modern Methods of Plant Analysis, vol. 2 (Ed. by K.Paech and M. V.Tracey). Springer, Berlin .
  • Hendricks, S. B. & Borthwick, H. A. (1959). Photo-control of plant development by excitation of two inter-convertible pigments. II. Theory and control of anthocyanin synthesis. Bot. Gas., 120, 187.
  • McEwan, J. M. (1954). A study of some Coprosma species of the Wellington area with special reference to natural hybridization. M.Sc. thesis, Botany Department, Victoria University College of Wellington.
  • Pecket, R. (1959). The constituents of leaf extracts in the genus Lathyrus and their bearing on taxonomy. New Phytol., 58, 182.
  • Smith, I. (1962). Chromatographic and Electrophoretic Techniques. Heinemann, London .
  • Turner, B. L. & Alston, R. (1959). Segregation and recombination of chemical constituents in a hybrid swarm of Baptisia laevicaulis × B. viridis and their taxonomic implications. Amer. J. Bot., 46, 678.