CERATORHIZA-PERNACATENA AND EPULORHIZA-CALENDULINA SPP NOV - MYCORRHIZAL FUNGI OF TERRESTRIAL ORCHIDS

Two new species of fungi mycorrhizal with terrestrial orchids native t o the Canadian prairies are described and illustrated. Ceratorhiza per nacatena sp.nov., from mycorrhizas of Platanthera praeclara, produces globose monilioid cells linked by narrow, tubular, connections that co ntain the septum between adjacent cells. Hyphae are binucleate, 5-7 mu m in width, regularly septate with perforate parenthesomes. Cellulase is produced, but polyphenol oxidase production is low to absent. Epul orhiza calendulina sp.nov., from mycorrhizas of Amerorchis rotundifoli a, is distinguished from other Epulorhiza species by the orange to och re colour of colonies on potato dextrose agar. On corn meal agar, clav ate to irregular monilioid cells are produced in short, branched, chai ns arising from lateral hyphal branches. Runner hyphae are binucleate, 3.0-4.7 mu m in width, regularly septate, with flattened, imperforate parenthesomes. Polyphenol oxidase production is lacking, but cellulas e is produced.