The New Zealand species of the Ericaceae and Epacridaceae examined possessed mycorrhizas anatomically similar to those of Calluna and Vaccinium. The endophyte of Pernettya macrostigma was isolated and successfully back inoculated into the host, under controlled conditions. Its taxonomic identity was uncertain because of its reproductive sterility. A fungus indistinguishable from the ericaceous endophyte was found to form mycorrhizas with Dicotyledons other than the Ericales.