Monday, May 23, 2011

Coeloglossum viride, Bracted Green Orchid

This is the elusive orchid long known as Habenaria viridis var. bracteata. More recently it has been called Coeloglossum viride var. virescens or var. bracteata, and now the USDA Plants database lists it as Dactylorhiza viridis. Common names include Bracted Green Orchid, Frog Orchid, and Satyr Orchid. Indiana’s legendary botanist Charles Deam found it in several counties, mostly in the northeast part of the state with outliers in west-central Indiana. It is listed as "threatened" in Indiana, and many authors say that it normally occurs as a single plant only.
The dorsal and lateral sepals of this orchid arch and converge to form a sort of hood above the column and lip. Viewed from above, it looks like the flowers are in bud but not opened. But if you put your face down by the ground and look up at the inflorescence, you can see into the open flowers! There is another greenish orchid with long bracts in the inflorescence: Platanthera flava. Care must be exercised when identifying either species; the morphology of the lip is perhaps the best field feature.






Scott Namestnik and I had the good fortune of seeing this plant in a state of FGB (full, glorious bloom) yesterday in a forest of hills and ravines near the Salamonie River. It is a challenge to find Coeloglossum in Indiana, and we owe a special debt of gratitude to Pete Grube, Jerry Sweeten, and Dave Hicks for helping us find it. The excellent discovery of this population was made by Tim Kimmel.





Remarkably, while I was attempting to get photos, Scott went exploring and found a small, sterile plant that could be a seedling of this orchid. Amazing! Of course, it could be something else, possibly a Liparis.




One of the best experiences for a botanist or a student of the flora is to visit a new site and learn lots of new species This is what happened on Sunday, and it was profoundly enjoyable!

9 comments:

A.L. Gibson said...

Awesome post! This is endangered in Ohio and been high on my 'life list' to see but haven't had any luck yet. I'll have to coax the location out of Scott sometime :)

Scott Namestnik said...

Nice post, Keith. I enjoyed seeing this species for the first time in Indiana. When we were at the site, I mentioned that I had seen it before in Colorado. My post on that find can be found at http://handlensandbinoculars.blogspot.com/2010/01/search-for-coeloglossum.html.

Andrew, let me know when you are in northern Indiana and maybe we can visit this site. Lots of other nice plants here.

Why is my word verification "geakiest"?

Pete said...

This orchid has been by nemesis for the past 10 years, so I'm most envious of your find, but highly impressed by your photos and observations of this species. Nice work.

Keith said...

Thanks Pete. I read somewhere that the flowers of this species last a very long time, so you might still be able to catch it in flower.

Prem Subrahmanyam said...

I can't tell from the photos...does this species have a spur/nectary from the back of the lip like Plat. flava? If not, that could also be used to identify the species.

---Prem

Keith said...

Coeloglossum has a pouchlike spur 2-3 mm, much shorter than that of Platanthera flava. The morphology of the lip on these two orchids is different in many ways.

Anonymous said...

Thank you for the discovery credit, but the plant was actually located by the keen eyes of ACRES stalwart Tim Kimmel.

Dave Hicks

Anonymous said...

Why is this plant threatened in Indiana? I am doing some research on the Coeloglossum viride var virescens. I can not find information on why it is threatened. Thanks

Keith said...

It has a widespread distribution in the northern half of the state, but rarely occurs in colonies. It is often just a single plant or two. My guess is that it's often overlooked, and by the way, because the flowers nod when open, they look look like they're finished unless you get down near the ground and look up at them.

In Indiana, endangered plants have one to five occurrences statewide; threatened plants have 6 to 10 known occurrences; rare ones have 11 to 20 known extant sites.