Missouri Orchids – A Trio of Tresses

Spiranthes cernua (nodding ladies tresses) found in Jefferson County, MO

I finished 2020 having found all but one species of Spiranthes orchid expected to be found in Missouri. Many thanks to John Oliver for giving me a bit of education and help in making correct identifications; however, any errors found here are my own and no one else should be blamed. I also want to thank John and Casey Galvin for giving me the clues as to where each species could be found. Identifying these was not as difficult as I originally expected, minus the exception pictured above.

Spiranthes cernua belongs to a species complex that is still being worked out. In addition, I have read that there may be up to 20 or more “races” within this particular species. Not that all of these races are found in Missouri, but generally, this species blooms with leaves. I had a hard time coming to the correct ID because the plants I had found had no leaves at bloom. It took me some time to find out that there is a race in Missouri that does indeed bloom without leaves being present. I will stop here as I cannot speak in more educated terms about this plant other than to say I that I found it stunning.

Spiranthes magnicamporum (Great Plains ladies tresses) photographed in Franklin County, MO

Found across much of northern and southwestern Missouri on limestone glades and other calcareous substrates, Spiranthes magnicamporum, or the Great Plains ladies tresses was only just recently separated from S. cernua. It is distinguished from S. cernua not only by a few morphological floral characteristics, but also by its fragrance. S. cernua is either fragrance free, or with only a hint of olfactory cues, while S. magnicamporum typically exudes a lot of fragrance. On just the right day one may be able to find it by nose before finding it by sight. I found it to have strong vanilla and coumarin hints.

Spiranthes magnicamporum (Great Plains ladies tresses) photographed in Franklin County, MO
Spiranthes magnicamporum (Great Plains ladies tresses) photographed in Jefferson County, MO
Spiranthes magnicamporum (Great Plains ladies tresses) photographed in Jefferson County, MO
Spiranthes magnicamporum (Great Plains ladies tresses) photographed in Jefferson County, MO. Note the widely spreading lateral sepals that arch above most of the flowers, a floral trait that is distinctive to the species.

The flowers of the next Spiranthes, little ladies tresses (Spiranthes tuberosa) were described perfectly by Homoya as “jewelaceous”. Here he was referring to the jewel-like look that a magnified view of the flowers have. Many orchid flowers have this look, with each of the “jewels” being composed of individual cells. This is one of the daintiest of orchids found in the state. In Missouri, they are found in dry, sandstone habitats away from competition. Although quite small, when in bloom they should be easy to find as they stand virtually alone in brutal xeric habitat.

Spiranthes tuberosa (little ladies tresses) found on private sandstone glades in Jefferson County, MO.
Spiranthes tuberosa (little ladies tresses) being visited by an halctid bee, one of its primary pollinators.
Spiranthes tuberosa (little ladies tresses) with a crab spider, lying in wait for a solitary bee to visit.