Native Orchid

I was walking around my front yard talking on the phone this week and I reached down and plucked a flower stem off of a "weed" growing in my yard.  As I was walking around I started looking at the flower spike a little more closely and noticed that the flowers were very intricate and attractive, although very tiny.  In fact, they looked a lot like an orchid.

Spiranthes lacera var. gracilis

The flowers spiral up the stem as they open and are all white, except for some yellow in the "throat."  I emailed a picture to my orchid friend, Steve, who lives in Arkansas.  He knows a lot about miniature orchids and natives, so I thought he might be able to give me some guidance.  He was familiar with my plant and told me it is called "Nodding Ladies' tresses" from the genus Spiranthes, possibly Spiranthes cernua.  There are a couple of other species that look very similar, as well.

[2010-09-24 Update:  I got a positive species identification on this plant.  It is Spiranthes lacera var. gracilis.  Thanks to the Native Orchid Conference mailing list for the ID help!]

Steve said that he has seen these in his yard before too and that he is amazed by their hardiness and survivability in mowed lawns.  Since I plucked mine before realizing what it was, I don't really know where I grabbed it or what the rest of the plant looks like, but Steve tells me it is a very non-descript grass like plant.  I'll keep my eyes peeled for more flower stems.

The USDA website shows that this plant is native to much of central and eastern North America.