Two new species of fungi mycorrhizal with terrestrial orchids native to the Canadian prairies are described and illustrated. Ceratorhiza pernacatena sp.nov., from mycorrhizas of Platanthera praeclara, produces globose monilioid cells linked by narrow, tubular, connections that contain the septum between adjacent cells. Hyphae are binucleate, 5–7 μm in width, regularly septate with perforate parenthesomes. Cellulase is produced, but polyphenol oxidase production is low to absent. Epulorhiza calendulina sp.nov., from mycorrhizas of Amerorchis rotundifolia, is distinguished from other Epulorhiza species by the orange to ochre colour of colonies on potato dextrose agar. On corn meal agar, clavate to irregular monilioid cells are produced in short, branched, chains arising from lateral hyphal branches. Runner hyphae are binucleate, 3.0–4.7 μm in width, regularly septate, with flattened, imperforate parenthesomes. Polyphenol oxidase production is lacking, but cellulase is produced. Key words: orchid mycorrhizas, Amerorchis rotundifolia, Platanthera praeclara, Rhizoctonia.
A 20-Year Record of the Western Prairie Fringed Orchid (Platanthera praeclara): Population Dynamics and Modeling of Precipitation Effects
