Southwestern Region

Rare Orchid New to the United States Doing Fine on the Lincoln National Forest

The leaves of Microthelys rubrocallosa.
The leaves of Microthelys rubrocallosa emerge from the ground after summer rains. Photo by Tyler Johnson.

The fruits of Microthelys rubrocallosa.
This plant has plump fruits indicating good seed production. Photo by Tyler Johnson.

In August, 2004, botanist Marc Baker discovered an orchid on the Lincoln National Forest that he could not identify, so he asked his friend and orchid expert Ron Coleman for help. It was a year later before Coleman could find plants suitable for an accurate identification. He determined the orchid was Microthelys rubrocallosa, a close relative of the ladies’-tresses orchids in the genus Spiranthes. This orchid had never been seen in the United States. Previously, it was only known from a few collections in the Sierra Madre of Chihuahua, Mexico, some 270 miles to the south.

Lincoln National Forest botanist Tyler Johnson has been visiting the orchid site regularly and reports that the small population of about 20 plants appears to be stable. It is difficult to monitor these plants because they are very small and appear above ground only as leaves, only as short-lived flower stalks, or not at all in dry years. Tyler has found flower stalks with swollen capsules indicating good seed production. The plants are in a lightly forested area that has little disturbance, but did have a forest fire burn through the area in the last 10 years. The Lincoln National Forest will continue to monitor these interesting little plants and search for others at similar sites on the forest.

For More Information

  • Coleman, R.A. and M. Baker. 2006. Microthelys rubrocallosa, a new addition to the orchid flora of the United States. Orchids: The Magazine of the American Orchid Society 75(1):56-57.
  • Tonne, P. 2008. Microthelys rubrocallosa taxon report. New Mexico Rare Plants at http://nmrareplants.unm.edu