As home to two species of native orchids, Filoha Meadows Nature Preserve’s contributions to the world of plant ecology are extending beyond its borders. This year, the open space was again tapped to provide plant samples and seeds for a national effort to conserve the orchid heritage of the United States and Canada.
Botanist Denise Wilson, who collected orchid seeds from Filoha last fall, returned twice this year to collect specimens for the National American Orchid Conservation Center – a coalition of organizations that have joined forces with a common goal: ensuring the survival of orchids for future generations. The specimens are being held at the Smithsonian Environmental Research Center.
Filoha boasts populations of both the stream orchid (Epipactis gigantea) and the western bog orchid (Platanthera tescamnis). The tiny flowers of both species are a highlight of summer educational tours at Filoha Meadows, a Pitkin County open space with limited public access and a lengthy seasonal closure to protect wildlife. The property is closed Oct. 1 through June 30.
The stream orchid is considered critically imperiled in Colorado because of the relatively small number of populations in the state. The Filoha population, however, numbers about 300,000 plants, a 2018 study of rare plants at the open space concluded. That makes it the largest known population of stream orchids in Colorado.
Wilson, who wrote a master’s thesis on “The Pollination Biology of the Stream Orchid,” follows specific protocols in the process of collecting specimens. For example, three capsules (each containing thousands of seeds) from genetically distinct individual plants are collected and labeled. The seeds of each plant are carefully segregated, as the future recovery of an orchid population would require genetic diversity in order to produce a healthy, stable population.
Leaves from both the stream and bog orchids have been sent to Illinois College for DNA analysis. The herbarium specimens – the entire plant from root to flower will also be archived.
The roots allow researchers to isolate the mycorrhizal fungi associated with a plant, identify it and, hopefully, propagate it. It’s a key step to future propagation of the orchid itself, as the fungi associated with a particular orchid species must be present for the growth of an orchid. Seeds alone won’t do the trick, as orchid seeds contain no endosperm – the tissue that is produced inside the seeds of most flowering plants after fertilization, providing the nutrition needed to make the plant grow. The growth of an orchid instead requires both the seed and the specific mycorrhizal fungi. The fungi (that’s just plural for fungus) exists in a symbiotic relationship with the plant root. The fungi send filaments into the surrounding soil to extend the roots’ ability to absorb nutrients and moisture from the soil. In return, the fungi receive nutrition from the plant.
In other words, Wilson explained, “Mama orchid does not pack a lunch for her kids. Instead, orchids have evolved with thousands of dust-like seeds which can be borne on the wind, and have been found 10,000 feet up in the atmosphere on wind currents.”
Those seeds won’t produce orchids, though, unless the encounter the required fungi. The National American Orchid Conservation Center attempts to collect both seeds and the associated fungi since both are key to propagating an orchid species. The center, in its lab, maintains the largest collection of living orchid mycorrhizal fungi.
NAOCC collaborators support efforts to preserve orchid habitats, and work with land managers to restore native orchids where populations have declined. According to the center’s website – northamericanorchidcenter.org – most orchid research and propagation efforts have focused on the tropical species of orchids, while research on the kinds of orchids that grow in the U.S. and Canada has been limited to small numbers of individuals, educational institutions and botanical gardens.
“The pace of research and conservation efforts relative to native orchids in the U.S. and Canada is far too slow to assure the survival of more than 50 percent of all native orchids that have been listed as threatened or endangered,” according to the NAOCC.
Efforts to ensure the survival of the species that flourish at Filoha Meadows Nature Preserve, however, is under way.
– By Pitkin County Open Space and Trails