Thursday, September 25, 2014

Ladies'-tresses Orchids

Photo by Mark Bower
We recently had the pleasure of botanizing at Bull Mills with Doug Ladd of the Nature Conservancy.  While we were standing in the cemetery and I rambled on about the history, Doug turned around and pointed out a few tiny orchids standing above the mowed grass, something that none of us had noticed.  These were slender ladies'-tresses orchids Spiranthes lacera, a genus he had discussed at our Master Naturalist meeting in June.

Identifying orchid species can be intimidating but ladies'-tresses are distinctive.   The genus Spiranthes comes from the Greek speira, meaning "coil". Their inflorescence (cluster of flowers) is arranged in a spiral down the stem.  I was able to identify it as S. lacera because of the distinctive green or yellowish-green spot on the center of the labellum (lower modified petal).*

Photo by Mark Bower
The details of the tiny petals were impossible for me to capture with my equipment so I called Mark Bower.  He came down the next morning and took these beautiful pictures which show the orchid's distinctive features.  You can easily see the "yellowish-green spot on the center of the labellum" that was hard to see at ground level with a magnifier.

S, lacera range- Wikipedia
Orchids, like bobcats and black bears, are what I think of as common yet uncommon Ozark species.  If you look at a range map, orchids occur over the Eastern US and Canada and yet we haven't seen them before and native plant enthusiasts will make field trips just looking for them.  Their brief period of flowering and diminutive size lead to their infrequent discovery.  Even on the mowed grass we had a hard time finding all of them.  However once you've seen one you are much more likely to recognize another.  On subsequent days Barb found them while eliminating some sericea lespedeza between  trees bordering a bottom land field and under a power line cut.

Photo by Mark Bower has details.

What is it?
Below is a photograph I was sent by our friend Georgia, who found it on the edge of her dog's water bowl.  She asked me what it was and I was way off with my first guess.  Now you can try before we answer it in a posting next week.
Animal, vegetable or mineral?

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