Botrychium pumicola or pumice grapefern is a rare and unique fern in the family Ophioglossaceae that is endemic to Central Oregon.
The usual facts: Pumice grapefern occurs in 2 habitat types: alpine sites like the Crater Lake rim, and montane sites, including frost pockets and lodgepole pine basins. This plant is considered “Sensitive” by both Oregon/Washington BLM and Region 6 of the Forest Service. The species is also a State threatened species, through the Oregon Department of Agriculture, and is a G3, S3, List 1 species through rankings by NatureServe and the Oregon Biodiversity Information Center. It occurs on Fremont-Winema National Forest, Deschutes National Forest, as well as, Prineville District (Bureau of Land Management) and Crater Lake National Park. There are around 30,000 pumice grapefern individuals estimated to exist over the entire range of the species.
Some unusual facts: The ecology of this species is extremely interesting and mysterious! This fern is dependent in some stages of its life cycle on one or more species of Glomalean fungi as a mycorrhizal partner. It has specific darkness requirements for spore germination. There are several types of propagules, some of which can survive underground for a number of years. This in turn means that plants do not emerge from the ground in the same place every year, if at all. And so it requires special field skills to work with it (patience, dedication, appreciation of small plants, ability to withstand thick clouds of mosquitoes while crawling through lodgepole thickets, etc).
Some hard truths: Management of pumice grapefern can be very challenging, but efforts are being taken to protect and maintain the habitat for this plant. Also due to the many strange and wonderful botanical terms used to describe this plant there is considerable danger that your inner plant geek will be exposed!
If you would like to know more about this very unique plant and efforts to conserve it, please come to the NPSO Klamath Basin Chapter meeting on March 6 at 6:30 pm! The presentation will be led by Missy Anderson, a botanist with the Fremont-Winema National Forest.