Wednesday, March 16, 2011

Blunt-leafed Rein Orchis (Platanthera obtusata subsp. obtusata)

This is one of the easier Platantheras to identify since its 1 cm flowers are whitish in color and of a different shape from P. dilatata, aquilonis, huronensis, stricta and such species.  It is also much smaller in plant size, rarely more than 30 cm tall.

It can also be identified by the fact that it has only one leaf near the base of the plant and by the fact that it is often found in woodlands rather than open marshy areas.  There is a smaller, fewer-flowered subspecies, but that is confined to northern Alaska and Eurasia.

The species is found across Canada and in the United States only in Alaska, Washington, Idaho, Montana, Colorado, Massachusetts, and the upper Great Lakes region.  It increases in numbers the farther north one traces it, being rare in the southern parts of its range.


  1. I just found your fantastic blog! Thanks for sharing such beautiful pictures and information.
    I'm a post-doc researcher at UW and I'm currently working on orchid scent and the way they get pollinated by mosquitoes. I'm looking for Platanthera obtusata in the Washington state and I was wondering if you knew areas where I could find some? The main idea is to collect their scent using a non-invasive technique. The plants won't be cutted or removed.
    Thanks for your help!

    1. Hi Chloe. If I knew where to find this in Washington, I'd tell you. It's reported from our state but we cannot find it anywhere. The best leads are for Colville National Forest and we know someone who is working there now and looking for it, but have not found it. These were photographed in British Coilumbia - Mount Robson Provincial Park.

    2. You are welcome and sorry I couldn't be of more help.