Locally rare orchid among Filoha’s delights

May 29, 2019

One of Filoha Meadows’ most significant attributes is also among its most diminutive. In fact, visitors regularly get down on hands and knees and use a magnifier to get a better view.

The locally rare stream orchid (Epipactis gigantea) was among the surprises discovered at Filoha Meadows Nature Preserve when Pitkin County began assessing the area’s plant and animal communities after the property was acquired with land purchases in 2001 and 2003. The plant is a highlight of summer tours on the property, led by the Roaring Fork Conservancy in partnership with Pitkin County Open Space and Trails, where visitors are encouraged to kneel and take a closer look at the sublime blossoms of this distinctive plant. These special tours (see the 2019 summer schedule below) are the public’s only opportunity to get a firsthand look at the orchids.

Filoha first opened to limited public access in 2010, but no long-term studies had been conducted to document the health of the stream orchid population at the Preserve. That changed in 2018, when the plant was the focus of an in-depth monitoring project that sets the stage for future assessments of the stream orchid population at Filoha. Long-term monitoring by botanists/ecologists will show whether the orchid population is increasing, stable or declining at the Preserve.

The first year of monitoring, however, produced a stunning conclusion: The population of stream orchids at Filoha likely numbers about 300,000 – by far the largest population of this plant species recorded in Colorado.

The stream orchid, also known as false helleborine orchid or “chatterbox orchid” (because the flower’s lower lip vibrates easily when moved) is a wide-ranging species, occurring from British Columbia through the western United States and with at least one collection in Mexico. It occupies a variety of habitats. All occur near water, though, including marshes near hot springs, which is the case at Filoha. Because the plant occurs in isolated populations scattered over a broad geographic range, it appears the populations are genetically distinct.

While the species is considered “apparently secure” on a global level, given the large number of existing populations, it is considered critically imperiled in Colorado because of the relatively small number of populations within the state. The U.S. Forest Service lists it as a “sensitive species” in the region.

Monitoring of the plant at Filoha included mapping the occurrence of stream orchids on the property and assessing the overall number of the plants. Potential threats to the orchids were also analyzed. Chief among them is disruption to the mineral-laden hot springs that flow year-round in the wetlands.

Another threat to the species may be its reliance to one type of pollinator – two species of syrphid flies are the only insects documented carrying and transferring stream orchid pollinium (a mass of pollen grains) at Filoha. Invasive plants that have the ability to compete with the stream orchids also pose a threat. Pitkin County is currently funding an experimental weed control study to look at different methods of controlling noxious weeds without harming the orchids. Finally, ecologists concluded the genetic variation among the orchid plants at Filoha could be low, while high genetic variability within a population is beneficial for its long-term persistence.

While scientists continue to monitor the stream orchids and other unusual plant species at Filoha Meadows, the public is invited to enjoy these wonders purely for the delight they provide.

Open Space and Trails sponsors annual tours of the property, led by Roaring Fork Conservancy, that provide a visitor’s only access to the wetland areas of Filoha. The programs also provide a glimpse of another rare sighting in the Colorado mountains – fireflies that flit through the wetlands as darkness falls.

The programs are free, but registration at www.roaringfork.org/events is required.

Find out more about Filoha Meadows.


JUNE (all 7:30-9:15 p.m.)

JULY (all 7:30-9:15 p.m.)

AUGUST (all 9:30-11:30 a.m.)

SEPTEMBER (4:30-6:30 p.m.)

By Pitkin County Open Space and Trails