Statistics for The biogeography, ecology and endophyte mycorrhiza of the New Zealand Corybas alliance (Orchidaceae) : specifically, Nematoceras iridescens (Irwin et Molloy) Molloy, D.L.Jones & M.A.Clem. (species) : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Plant Biology at Massey University, Palmerston North, New Zealand