Dr. Karen L. Johnson – (Retired) Curator of Botany

Assisted by other staff and volunteers, Dr. Johnson studied and tagged population (originally 100 plants) of the nationally and provincially endangered Western Prairie-Fringed Orchid (Platanthera praeclara) beginning in 1987. The site is part of the Tallgrass Prairie Preserve, located in southeastern Manitoba near Tolstoi and Vita.

The Western Prairie-Fringed Orchid is a large, showy plant, reaching one metre in height and with up to 20 fragrant white flowers. It is one of several rare and endangered plants found in the transitional Parklands/Mixed Woods region. The Manitoba orchids are the only ones in Canada and are at the northern end of the plant’s range. They form one of three metapopulations (over 1,000 individuals) found in North America. Ours is probably the largest metapopulation, with 20,000 flowering stems counted in 1996.

This orchid was not officially reported from Manitoba until 1984. Although residents of the region recall seeing them before then, we have no records of the orchid occurring in the former tall-grass prairie region. Being such a spectacular plant, it is not likely to have been overlooked by early botanists. So it probably never occurred outside its current small area in the province and may not have even been present in Manitoba until recently.

Another metapopulation occurs in northern Minnesota, some 70 km south of the Tolstoi area. Our orchids may have migrated north from these plants as seeds in the wind or on a bird’s foot. DNA testing is presently being done to determine the relationship of the Manitoba population with the one in Minnesota.

Not much is presently known about the biology and ecology of this orchid, but this information is needed if we are to preserve it in the future. Our study was expanded in 1994 by tagging nearly 500 new flowering plants. The number of flowers and leaves, stem height and number of seed pods are recorded for each tagged plant. All individual orchid plants, flowering and non-flowering, were also tagged and recorded in a smaller intensive study plot to determine the total loss and gain of orchids in a known area.

We already know there is great variation (3 to 1,500 plants) in the number of flowering orchids on any given site over the years. This study is trying to determine what causes these variations. Climate, including droughts and late frosts, could well be the major factor controlling the northern and western limits of many plant species in the Parklands\Mixed Woods region, including this orchid.

Information from the study, including photos and video clips of the orchid and research process, may be included in any or all of the following gallery units: – “The Ecology of the Parklands\Mixed Woods Region” as one of the unique plants of the area.