Platanthera praeclara

The western prairie fringed orchid or Great Plains white fringed orchid concludes the orchids of Manitoba series. Photographed at the Tolstoi Tall-Grass Prairie Preserve less than two weeks ago, this was one of only two plants we saw in flower. In a typical year in early July, I was told there should be hundreds in bloom, if not thousands. We spoke with someone in the area who had managed the land parcels for a couple decades: “It’s the worst year I’ve ever seen [for blooms]”. This, of course, was after walking a trail with ticks on a hot and muggy morning to find no discernible plants. Slow drives along the roadsides where the retired land parcel manager suggested they are typically easily found yielded no results. Finally, about 400m before the return to the highway and the trip back home, I spotted one.

While preparing to photograph it, Christie Borkowsky, a biologist with Manitoba’s Critical Wildlife Habitat Program, happened to drive by. I had met Christie several weeks earlier while unsuccessfully looking for Cypripedium candidum in bloom (plants were found). On this day, she was working on plant counts for this species. Her count? About ten. She confirmed that the count would normally be in the hundreds, if not more. Christie has been working with Platanthera praeclara for at least a decade, initially studying pollinators of the western prairie fringed orchid. For a more in-depth look at her research, see Westwood, AR and CL Borkowsky. 2004. Sphinx Moth Pollinators for the Endangered Western Prairie Fringed Orchid Platanthera praeclara in Manitoba, Canada. (PDF) Journal of the Lepidopterists’ Society. 58(1):13-20. As Christie was driving away, she pointed out the second plant in flower we saw that day about 40m down the road.

Platanthera praeclara is known only from the Great Plains of the USA and Manitoba (despite the broad range shown on the distribution map, it seems it has been declared extirpated in both South Dakota and Oklahoma). It is considered endangered in both the Canada and the USA, and is ranked A2ac by the IUCN Red List (Platanthera praeclara, meaning “An observed, estimated, inferred or suspected population size reduction of ≥ 50% over the last 10 years or three generations, whichever is the longer, where the reduction or its causes may not have ceased OR may not be understood OR may not be reversible, based on direct observation and a decline in area of occupancy, extent of occurrence and/or quality of habitat”. The section on populations of Platanthera praeclara on the IUCN site discusses both year-to-year fluctuations and overall declining trends in the species. For example, in Manitoba: “The number of plants occurring in Manitoba is difficult to determine because of dramatic fluctuations in numbers from season to season. A low of 1,818 plants were counted in 1995 and a high of 23,530 were recorded in 2003. Fluctuations in the number of flowering individuals are very common for this species, however, it is the overall decline in the numbers of reproductive individuals at each fragmented location which is of biological concern”. I suspect 2012 will show a new low for Manitoba. Though we speculated as to why (perhaps the late frosts in the area (the ones that damaged the blooms of Cypripedium candidum or the heat in early spring followed by cool weather), it would require study since there are so many potential variables.

If you’ve enjoyed the series on orchids of Manitoba, you might like to visit the site of Manitoba’s Native Orchid Conservation Inc., a non-profit organization whose purpose is “to protect unique mini-ecosystems and their plant communities. This primarily involves native orchids but can also extend to other rare and/or endangered plants”. Their web site contains many additional photographs of Manitoba orchids and their Orchids of Manitoba: A Field Guide is an excellent resource if you can’t resist top-notch field guides (like me).

Platanthera praeclara
Platanthera praeclara

7 responses to “Platanthera praeclara”

  1. Elizabeth

    Wow- Stunning work Daniel. I really enjoyed this series on Orchids. Never knew that Manitoba held such beautiful and diverse Orchid species! They all look so exotic!!
    As always, the photo quality is remarkable- I really feel the work and appreciation for each plant that you put into every (published) shot.
    What a treat it must have been to search out and witness these orchids- this one in particular. It’s like some sort of alien bird!!
    Thanks 🙂

  2. Don Fenton

    What a lovely little pretty! Has there been any work done on cultivating these for reintroduction to some of their former haunts? In at least some Australian States there are “tuber banks” from which landowners, conservation groups and authorities can access many species of ground orchids, and specialist nurseries can also supply a large variety of nusery-grown plants.

  3. Elizabeth Revell

    That is such a beauty! Is the fine webbing inside the flower an inherent part of it? The stem looks as if it might grow quite tall, so how much would it normally stand out?

  4. elizabeth a airhart

    thank you daniel i rather think i have found orchids that i like
    i do like wild flowers the little ones that grow on a small bark
    of a tree are ever so nice to have and take little space
    perhaps this is the bird of paradise how ever we all got here
    not to bad a place to be not to bad at all good night from florida usa

  5. Christie

    Great photos and article Daniel! Glad you found a couple of plants to photograph. We almost have all the numbers tallied and I’ll send it to you offline.
    To answer E. Revell’s question about the webbing inside the flower on the second photo, no the webbing is from a small spider. It’s fairly common to find different species of spiders among the flowers of the fringed-orchid. Sometimes these webs will blocks off the opening to the nectar spur, stimagmatic surface and pollinaria by keeping the petals from spreading apart to their full extent.
    These orchids typically grow about 30-40cm tall but the largest I’ve ever encountered was 75cm tall…I have no idea what happened to produce such a “giant” flowering fringed-orchid, it all had over 20 flowers which is also extreme, usually there are 5-7 flowers.

  6. Kathy Driggers

    Do you they know why the flower count is so low this year? And why is there such a reduction in the number of plants? What has impacted this lovely orchid?

  7. Fred Bess

    I helped Ohio DNR count the Platanthera leucopheae Eastern Prairie fringed orchids a couple weeks ago in Holmes Co. Ohio. like you normally we count in the hundreds. This year 14 flowering plants. Here’s hoping we all have better counts in 2013!

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