Date of this Version
The Prairie Naturalist· 42( l/2): June 20 I 0, pp 50-54
In 1989, the U.S. Fish and Wildlife Service listed the western prairie fringed orchid (Platanthera praeclara) as threatened. Although this orchid has been monitored for years, there is little scientific documentation of its biology, ecology, and phenology, nor the impacts of management activities on its populations. Our objectives were to document seed germination and seedling production rates after one year in situ, and compare seed germination in grazed and non-grazed prairie habitat in the Sheyenne National Grassland (SNG) in southeastern North Dakota. Of 18,717 planted seeds, we recovered 1,561 swollen embryos, 94 protocorms, and 51 seedlings. We documented no difference in germination rate between seeds planted in grazed versus non-grazed prairie. However, our results suggested that 15 new flowering orchids may be produced from each flowering orchid that survives the growing season on the SNG. Thus, our findings confirm successful production of western prairie fringed orchid seedlings after one year in situ. Further research is needed to evaluate potential impacts of livestock grazing on other stages of the orchid life cycle, particularly protocorm and seedling survival rates.