Environmental parameters influencing the distribution of Platanthera blephariglottis and Platanthera clavellata (Orchidaceae) in peatlands on the Avalon Peninsula, Newfoundland

Populations of two terrestrial species of orchids, Platanthera blephariglottis (Willd.) Lindl. and Platanthera clavellata (Michx.) Luer, were investigated for two field seasons (1991-1992) to determine what environmental factors (substrate constituents, water pH, water level) may influence their distributions within a peatland. Feat constituent values (magnesium, phosphorus, nitrogen, potassium, iron, calcium, pH, moisture, organic matter, ash) associated with individual species were, for the most part, not significantly different among sites or between species, although the values associated with P. clavellata tended to be higher and to have a greater range than those associated with P. blephariglottis. Water level values associated with species were significantly different between species, suggesting that it is on this basis that these species partition their habitat.