Goal 1
This conservation assessment aims to consolidate current understanding of the biology and ecology of Platanthera chorisiana, identify threats to the species, and outline conservation strategies to support federal management efforts for its long-term survival.
This species is of conservation concern because of its low numbers of individuals, limited distribution in Washington State, and impacts from unregulated recreation.
Scope 1
This conservation assessment provides a comprehensive overview of a lesser-known vascular plant species, focusing on its distribution and status in Washington State, particularly on federal lands It also incorporates relevant data from nonfederal lands to enhance understanding and support the overall conservation efforts for the species.
Recent years have seen a significant increase in knowledge about this species, particularly concerning its distribution and habitat To maintain the accuracy of this assessment, ongoing updates will be essential Additionally, the identified threats reflect both known and potential risks, which may evolve over time Acknowledgment of uncertainty and inference is included where relevant.
Management Status 1
Systematic and Synonymy 2
Adelbert von Chamisso (1828, Appendix 1) first described what is now Platanthera chorisiana as Habenaria chorisiana from the type locality “mountainous regions of
Unalaska.” The holotype was collected by Johann Freidrich Eschscholtz.
The genus name Platanthera translates to "broad anther," reflecting its botanical characteristics, while the specific epithet chorisiana pays tribute to Louis Choris, a Russian painter Choris, along with Chamisso and Eschscholtz, participated in the Russian Rurik expedition, which aimed to discover a Northeast Passage from Russia to Alaska via the Bering Strait.
Inoue (1983) noted that a taller and more robust variant of P chorisiana has been classified either as a separate species (P ditmariana) or as a variety (var elata), but he does not accept these classifications due to the presence of both forms and intermediates within the same populations Current nomenclature adheres to the classifications established by Inoue (1983) and Sheviak (2002).
Synonyms: Habenaria chorisiana, Peristylus chorisanus, Pseudodiphyrullum chorisanum, Limnocharis chorisiana, Platanthera ditmariana
Common names: Choris’ bog-orchid, Chamisso bog-orchid
Species Description 2
Life History 4
Inoue (1981, 1983) reported that Platanthera chorisiana was pollinated by a small beetle,
Oedemeronia lucidicollis Motschulsky (Oedermeridae) on Rebun Island, Hokkaido
In the Prefecture of Japan, research indicates that the short spurs of the orchid, measuring less than 2 mm, allow short-tongued beetles to access its nectar Inoue proposes that these beetles not only consume nectar but also utilize pollen, as evidenced by the presence of pollinia attached around their mouths and between their antennae.
The Oedemeridae family, known as pollen-feeding beetles or false blister beetles, primarily consume pollen and nectar, while their larvae typically inhabit decaying wood, with some residing in soil tubes Although various Oemerideae species are found in regions like Alaska, British Columbia, and Washington State, O lucidicollis is absent from North America, leaving the pollination of P chorisiana uncertain Research indicates that the pollinia of P chorisiana come into direct contact with the stigma, showing visible pollen tubes This orchid exhibits floral characteristics typical of autogamous species, including nearly closed flowers, a lack of a rostellum, poorly developed viscidia, and pollinia directly touching the stigmatic surface.
Autogamy is rare in the Platanthera genus, with only two out of 19 species, Platanthera clavellata and P integra, identified as self-pollinating Research by Patt et al (1989) indicates that Platanthera stricta in Washington State relies on insect pollinators, although self-pollination, intraracemic, and interracemic pollination can all aid in seed production Notably, seeds from self-pollination and intraracemic pollination exhibited significantly fewer embryos compared to those from interracemic pollination and insect-pollinated treatments.
Orchids possess tiny seeds that contain minimal food reserves and depend on a fungal association for nutrition During germination, the seeds absorb water, causing the embryo to swell and break through the seed coat This process leads to the formation of a protocorm, an undifferentiated structure that will later develop into leaf and root primordia Without fungal infection or an external sugar source, the germination process halts at the embryo or protocorm stage.
Rasmussen and Whigam (1998) note that terrestrial orchids may have a prolonged
The "underground stage" of a seedling involves breaking seed dormancy, fungal infection, and the development of plant organs before emerging to the surface During this phase, which typically lasts 2-4 years (Rasmussen and Whigam 1998), the seedling relies entirely on its fungal associate for nutrition However, Sheviak (2005) notes that while these plants spend at least one year underground, they tend to be short-lived above ground, suggesting that the visible leafy plants may only be transient members of the population This indicates a continuous replacement of above-ground plants by their underground counterparts.
The specific germination and establishment requirements of P chorisiana remain unknown However, an in vitro study on California species Platanthera saccata and P hyperborea revealed slow germination and development rates across various culturing conditions, with protocorms emerging between 2 and 23.5 months, rhizomes between 11.75 and 23.5 months, and shoots between 13 and 28 months (Arditti et al 1981) Additionally, seeds of the prairie species P praeclara did not germinate without a cold stratification treatment (Sharma et al 2002).
Platanthera chorisiana flowers between July and August in Washington State
Range, Distribution, and Abundance 6
Platanthera chorisiana is distributed over a wide area, ranging from Japan through the
The species is primarily found in the Aleutian Islands and extends southward through the Queen Charlotte Islands, Vancouver Island, and into British Columbia and Washington State According to Luer (1975), certain areas in the Aleutian Islands have a notable presence of this species, while Stensvold (2007) indicates it is commonly found in Alaska's muskegs, albeit not in large numbers In 2002, it was removed from the Sensitive Species list in Region 10 The only known occurrences in the continental United States are in western Washington, which are geographically isolated from the main range of the species, as it does not exist on the Olympic Peninsula or in Oregon.
In 1912, P chorisiana was collected from Lake Serene in Snohomish County, Washington, as reported by Hitchcock et al (1969) However, Fuentes (2007) clarified that the actual location of this discovery was near Mount Index, not Edmonds.
Occurrence number 002) is no longer considered valid by the Washington Natural
The Heritage Program has officially removed certain records, yet Lake Serene Element Occurrence number 003 continues to be recognized as a documented site Last monitored in 2002, this population has shown remarkable persistence in the area for over 90 years.
Grable and Laferrière (1993) documented the re-collection of P chorisiana in
Washington State in 1980 and 1986 on the Mount Baker-Snoqualmie National Forest
Eight of the ten extant element occurrences (Master et al 2001) are in Snohomish
The study identifies a total of eight sites, with two located in King County and six within the Mount Baker-Snoqualmie National Forest, while the remainder is managed by the Washington State Department of Natural Resources Notably, there are no sites on Bureau of Land Management (BLM) lands These sites are concentrated in a narrow longitudinal band, spanning from approximately 121° 42' 00" W to 121° 24' 00" W, covering a width of about 22 kilometers.
Between 1993 and 2003, a minimum of 719 stems of P chorisiana were recorded across ten occurrences It is important to note that many orchids, including P chorisiana, may experience a lengthy "underground stage," suggesting that their true abundance could be significantly higher than documented.
Population Trends 7
Monitoring has not occurred for a long enough period to make inferences about population trends in Washington State
Poodledog Pass, Lake Isabel, and Squire Creek Pass host the largest populations of P chorisiana, indicating these areas may offer higher habitat quality and act as vital "source populations" for local seedling recruitment However, despite revisiting the Poodledog Pass pond subpopulation and Upper Boardman Bog in 2002, no individuals of this species were found at these locations.
Washington populations of P chorisiana are at risk of extirpation due to their disjunct status from Alaskan and Canadian populations and the limited number of individuals present in the state The vulnerability to random environmental changes highlights the need for further research, particularly in understanding the species' pollination biology and the extent of gene flow between the isolated Washington populations and those in Canada.
The "underground phase" of orchids, as described by Rasmussen and Whigham (1998), is a critical and vulnerable life stage where seedlings rely entirely on their fungal associates for up to four years It is only when they emerge above ground that they begin to photosynthesize and produce their own food However, this above-ground "green phase" is also at risk; Sheviak (2005) highlights that even minor disturbances, such as cutting the leafy shoot for herbarium specimens, can result in the death of the plant.
Figure 2 Approximate range of Platanthera chorisiana in Canada and the United States
The North American range of the species extends from the Aleutian Islands and the interior of Alaska, moving south through the Queen Charlotte Islands and Vancouver Island, into the interior of British Columbia, and reaching Washington State.
Figure 3 Extant Element Occurrences of Platanthera chorisiana in Washington State Six
Element Occurrences can be found in the Mount Baker-Snoqualmie National Forest (MBS NF), with four additional occurrences located on lands managed by the Washington State Department of Natural Resources (WA DNR) The location data is provided by the Washington Natural Heritage Program (2005).
Table 1 presents the occurrences of Platanthera chorisiana across various sites in Washington State, detailing site names, counties, stem counts, land managers, and land allocations Notably, years with an asterisk (*) indicate plot counts derived solely from 1/50th acre plots Additionally, all occurrences within National Forests are situated in Riparian Reserves, with specific references to Mount Baker-Snoqualmie National Forest (MBS NF), Ranger District (RD), Washington Department of Natural Resources (WA DNR), and Natural Resources Conservation Area (NRCA).
County # stems by census year
003 Lake Serene Snohomish 14+ (2002) MBS NF, Skykomish RD Administratively Withdrawn (Mt Index Scenic Area)
Snohomish 214 (1998) MBS NF, Darrington RD Congressionally Withdrawn (Wilderness)
“rock outcrop subpop” Snohomish 10 (1992) MBS NF, Darrington RD Congressionally Withdrawn (Wilderness)
0 (2001, 2002) MBS NF, Skykomish RD Congressionally Withdrawn (Wilderness) Poodledog Pass
“steep meadow” Snohomish 3 (1983) MBS NF, Skykomish RD Congressionally Withdrawn (Wilderness)
005 Lake Isabel Snohomish 125 (2002) MBS NF, Skykomish RD Administratively Withdrawn
(Semi-primitive non-motorized dispersed recreation, Late Successional Old Growth)
Dollar Lakes Snohomish 3 (1993) MBS NF, Skykomish RD Administratively Withdrawn
006 Lake Elizabeth King 6 (2002) MBS NF, Skykomish RD Matrix
Crater Lake boot path King 3 (2002) MBS NF, Snoqualmie RD Administratively Withdrawn
007 Squire Creek Pass Snohomish 115+ (2002*) MBS NF, Darrington RD Congressionally Withdrawn (Wilderness)
0 (2001, 2002) WA DNR Mt Pilchuck NRCA
12+ (2002*) MBS NF, Snoqualmie RD Administratively Withdrawn
011 Bald Mountain Snohomish 7 (2003) WA DNR Morningstar NRCA
49 (2003) WA DNR Mt Pilchuck NRCA
013 Big Greider Lake Snohomish 54 (2003) WA DNR Greider Ridge NRCA
Habitat 11
Threats to the Species 13
Based on monitoring of the sites on National Forest land, the following threats are listed in order of likelihood and potential risk to the species.
Hiking, trail building, and maintenance often lead to trampling and other direct impacts that pose significant threats to fragile plant populations Many of these plants are located in recreational areas, with the highest concentrations found near trails and water bodies that attract visitors The proximity of four additional sites with smaller populations to trails and water further highlights the risk of damage These small, delicate plants are unlikely to withstand any direct impacts, as evidenced by Sheviak (2005), who noted that even the removal of a leafy shoot for herbarium specimens can be fatal to the plant Such findings underscore the detrimental effects of intensive recreational activities on these vulnerable species.
Lakes are often hotspots for visitors, leading to concentrated human activity in specific areas This prolonged presence can make these locations particularly susceptible to environmental impacts.
Habitat loss through changes in hydrology resulting from management activities is a include trail building, trail maintenance, road construction or decommissioning, and fire line creation.
Habitat loss through changes in pH or water chemistry could result in habitat loss Occurrences near mining projects could be affected by mine leachings The response of
P chorisiana to these variables is unknown.
A previous proposal for a hydropower project at Lake Isabel has been abandoned, yet the demand for National Forest System lands for such projects remains influenced by market conditions The lake's natural fluctuations contribute significantly to its diverse habitats, and implementing a hydropower project could harm the wetland ecosystem by altering the hydrologic regime Staying informed about potential developments and voicing concerns during the hydropower permitting and analysis process is crucial.
Habitat loss resulting from climate change is another possible threat The
The Intergovernmental Panel on Climate Change (2007) forecasts significant changes in climate patterns, including a reduction in glacier and snow cover, an increase in hot days and nights, and more frequent heat waves Additionally, there will be a growing area affected by drought and a rise in precipitation predominantly as rain Similarly, the Climate Impacts Group (2007) anticipates a warming trend in the Pacific Northwest, projecting an increase of around 0.5º F per decade, with the most pronounced temperature rises occurring during the summer months of June to August.
As winter precipitation increasingly occurs as rain instead of snow, we can expect earlier spring snowmelt, reduced summer stream flows, and more frequent droughts Climate models indicate that high-altitude forests will migrate upslope into meadows due to diminishing snowpack and earlier melt, facilitating seed germination and the growth of woody plants.
Climate change may alter hydrological conditions, potentially depriving obligate wetland species like P chorisiana of the necessary moisture for survival Additionally, these environmental shifts could impact the fungal associates and pollinators that are vital to P chorisiana's ecosystem.
Platanthera chorisiana could possibly indicate the effects of changes in the climate
Maze and Robson (1992) conducted monitoring to assess alterations in the hydrology of specific sites and to record shifts in vegetation cover and types However, there has been no monitoring of habitat loss related to these changes thus far.
Competition from Noxious Weeds and Other Introduced Plants
No noxious weeds or other introduced plants are currently known to occur at any of the element occurrences on National Forest System lands
However, in her sighting report of element occurrence 013 (Big Greider Lake), Holly Zox
Reed canarygrass, known scientifically as Phalaris arundinacea, is a highly aggressive species that frequently establishes persistent monocultures in wetlands and riparian zones Its invasive nature poses a significant threat to biodiversity, as it outcompetes and chokes out native plants The proliferation of this species, along with other aggressive introduced plants, can lead to the degradation of wetland habitats and negatively impact the survival of native species like P chorisiana.
Platanthera chorisiana is a species that exclusively thrives in wetland environments, making timber harvesting on National Forest System lands in these areas highly improbable However, populations of this orchid may face threats on privately owned or differently managed lands.
Based on visual inspections, no evidence of herbivory or disease was noted in visits to element occurrences in 2002 and 2003.
Conservation Status of the Species in Region 6 and OR/WA BLM 15
In Washington State, six out of ten known occurrences of P chorisiana are located within the Mount Baker-Snoqualmie National Forest, primarily situated in protected land areas These regions are designated with a Riparian Reserve, ensuring the preservation of wetlands where this species thrives, as outlined by USDA and USDI guidelines from 1994 and US Fish and Wildlife assessments from 1988.
The remaining four occurrences are on lands managed by the Washington State
The Department of Natural Resources designates Natural Resource Conservation Areas (NRCAs) to safeguard exceptional native ecosystems and provide habitat for endangered, threatened, and sensitive species, as well as to preserve scenic landscapes Consequently, Element Occurrences within these NRCAs receive protection to ensure the conservation of biodiversity and ecological integrity.
Although currently known only from Snohomish and King Counties in Washington State,
Platanthera chorisiana may potentially inhabit Whatcom, Skagit, Kittitas, Clallam, Jefferson, and Grays Harbor counties, supported by botany and ecology data from the Mount Baker-Snoqualmie National Forest, herbarium records, and insights from Nelsa Buckingham and Don Knoke The species shares common associates in these regions, indicating the possibility of suitable habitats Notably, Henderson (2007) highlights that P chorisiana has not been located in areas that were covered by continental glaciers during the last ice age.
Preliminary analysis indicates that potential habitat may occur in Olympic National habitat on both National Forest and BLM land This species is not currently suspected to occur in Oregon.
Habitat Quality and Species Abundance
The primary populations of P chorisiana are found at Lake Isabel, Squire Creek Pass, and Poodledog Pass While these locations may offer superior habitat conditions, the exact habitat features that attract the orchid at each site remain unidentified.
Because P chorisiana is at the southern edge of its range, it may be more vulnerable to changes in habitat as a result of management activities or stochastic events
Despite all Element Occurrences being located in protected areas, the orchids remain vulnerable to uncontrolled recreational activities Hikers often stray from designated trails, which can lead to unintentional trampling of these delicate plants Additionally, the construction and maintenance of trails may pose further risks if proper mitigation measures are not implemented.
Known Management Approaches 16
Management Considerations 16
Research, Inventory, and Monitoring Opportunities _ 19
The pollination mechanisms of Platanthera chorisiana in North America remain unclear While Catling (1984) indicates that this species is self-pollinating in British Columbia, Inoue (1981, 1983) suggests it is beetle-pollinated in Japan Notably, the beetle species Oedemeronia lucidicollis, which is associated with this pollination, is absent in North America Researchers collecting beetle visitors to Platanthera chorisiana should take precautions to avoid skin contact, as oedemerid beetles can cause contact blisters (Vaurie 1951, Nicholls et al 1990).
Germination requirements of the species, including dormancy breaking requirements and identity of the fungal symbiont(s), are unknown
A draft Conservation Strategy for P chorisiana was completed in 1993 (Potash, 1993)
Surveys conducted in the Mt Baker-Snoqualmie National Forest revealed only three documented sites of P chorisiana (Belfield, 1993) Notably, at or near these sites, three species were found to occur with high frequency: Elliotia pyroliflorus, Caltha leptosepala ssp howellii, and Spiraea splendens var splendens.
(Potash, personal communication Using these three species to filter through Ecology plot data, eight areas were chosen across the North Bend (now Snoqualmie RD),
University of Washington Rare Care Volunteer, located three new element occurrences not on National Forest lands in 2002 and 2003 by focusing on Snohomish County lakes.
Table 4 Documented occurrences of sites including the species Elliotia pyroliflorus , Caltha leptosepala ssp howellii, and Spiraea splendens var splendens that have been surveyed for Platanthera chorisiana
Ecology Plot # Site Name Survey Results
4601 Headlee Pass Trail Not found
2826 Little Heart Lake Not found
2723, 2725 Snoqualmie Lake Not found, but needs more survey because a lot of habitat is present
Areas meeting the criteria below should be considered high probability habitat for this species and could be surveyed:
1 Area supports a plant community that includes the following species:
Elliottia pyroliflorus, Hypericum anagalloides, Caltha leptosepala ssp howellii, and Spiraea splendens var splendens,
2 Area is bounded by steep cliffs, resulting in cold air drainages,
3 Area is in the same ecozone as the known occurrences, and
4 Area is within the same longitudinal band as the known occurrences.
An analysis of ecology program plot data, botany program survey data, and USGS 7.5-minute quad maps has revealed 15 new high-probability habitat areas within the Mount Baker-Snoqualmie National Forest.
Recent modeling of potential habitats has shown promise in predicting the occurrence of lichen and vascular plant species of concern, leading to new sightings of Hypogymnia duplicata and Coptis aspleniifolia All documented locations of P chorisiana are found in regions with high precipitation and low mean annual temperatures at sea level A well-constructed species habitat model can effectively identify and differentiate these critical areas.
Table 5 Other areas on the Mount Baker-Snoqualmie National Forest with high probability habitat for Platanthera chorisiana
Nelsa Buckingham (1993) highlighted several locations on the Olympic Peninsula that harbor common associates of P chorisiana Similar regions in Washington State, including Olympic National Park, North Cascades National Park, and Okanogan-Wenatchee National Forest, should be analyzed using GIS to identify suitable habitats for P chorisiana, followed by thorough inventory efforts to document additional occurrences of this species.
The Bureau of Land Management does not currently suspect P chorisiana on its
Washington State lands A more thorough analysis of Washington BLM lands could be conducted to see if potential habitat is present.
Seed banking is a potential solution to address population declines caused by climate change or human activities Collecting seeds of the tiny P chorisiana presents challenges, but the University of Washington's Rare Care program plans to undertake seed collection efforts at Lake Serene in 2007.
Bagley Lake Mt Baker RD
Clear Lake/Island Lake Darrington RD
Deer Creek Pass Darrington RD
Hawkins Lake Mt Baker RD
Independence Lake/North Lake Darrington RD
Twin Lakes Skykomish RD unnamed lake, North Fork Tolt River drainage
The Weden Creek Trail in Darrington RD highlights the need for regular census of the entire population (N) to assess its trends—whether it is increasing, decreasing, or stable Given the fragility of the species' habitat, it is crucial that these assessments occur no more frequently than every five years to prevent negative impacts from the monitoring process itself.
Monitoring plots were installed at Lake Serene, Lake Isabel, Lake Elizabeth, Crater Lake, and Squire Creek Pass in 2002 These plots could be re-censused.
Monitoring plots could be established at all new element occurrences of this species, following the same protocol that was used in 2002.
The top, pollen-bearing portion of the stamen.
Stalk-like structure at the base of the pollinia.
A structure formed by the united filaments and style in orchids.
A geographically isolated population or species outside of the range of other similar populations or species.
Areas of land with similar environments The ecozone is defined by the elevation of the lower limit of the Silver Fir zone.
In the context of NRIS, an element occurrence refers to a specific area of land or water where a threatened or endangered plant species is currently found or has been previously observed The State of Washington Natural Heritage Program typically defines an element occurrence as a population, although individual plants may also be documented as separate occurrences.
The stalk of the stamen which supports the anther.
Natural or human caused disturbances that likely may have impacts on the species habitat, its life cycle, microclimate, or life support requirements.
The original specimen from which the description of a new species is made.
ISMS database (Interagency Species Management System)
The interagency database, previously housing information on Survey and Manage species within the Northwest Forest Plan area, included crucial data on surveys, species locations, and their associated habitats and environmental conditions However, this database is now defunct and has been replaced by a new system.
Lance-shaped; much longer than wide, with the widest point below the middle.
Lowermost, often largest, petal of orchids.
Potential management activities designed to achieve the conservation of a species at a site Management considerations are not mandatory.
Monitoring involves gathering information to assess whether management actions align with established standards, guidelines, and legal requirements It serves to evaluate the effectiveness of these standards and ensure compliance with management policies.
NRIS (Natural Resource Information System)
The Forest Service utilizes a standardized set of corporate databases and applications across the nation to maintain essential natural resource data The primary repositories for information on sensitive species within the Forest Service are NRIS Fauna and NRIS TES Plants.
Two to four times longer than broad with nearly parallel sides.
Blunt or rounded at the tip, with the sides coming together at an angle of 90 degrees or more.
Egg-shaped in outline and attached at the broad end.
The probability of a species persisting in a specific geographic region over time is influenced by its role as an integral part of the local ecological community.
The female reproductive organ of a flower, typically consisting of a stigma, style, and ovary.
Mass of waxy pollen grains transported as a unit to orchids.
Extended forward, resembling a parrot beak.
First, tuber-like structure produced by germinating orchid seeds Mostly consists of undifferentiated cells.
A type of strategic survey It is a focused search conducted in areas where the target species is expected to occur.
The limits of the geographic distribution of a species.
Upside-down due to twisting of the pedicle, as like the flowers of some orchids.
An extension from the upper edge of the stigma in orchids that aids in gluing the pollinarium to the pollinator.
Leafless stem that arises from the ground level.
Attached directly, without a supporting stalk.
The term refers to the specific location where an individual or population of a target species is found, observed, or believed to exist, encompassing individual detections, reproductive sites, or local populations The definitions and dimensions of these locations may vary by species and often involve connecting nearby or functionally contiguous detections within the same geographic area Additionally, this term includes potential future locations, and it is also associated with other terms such as known site, species location, and element occurrence.
The portion of the pistil receptive to pollen.
The usually narrowed portion of the pistil connecting the stigma to the ovary.
The study and classification of organisms with the goal of reconstructing their evolutionary relationships and histories.
Different scientific names used for a single taxon.
The ability of wildlife or plant populations to sustain a viable size over time, despite natural fluctuations in numbers, is crucial for their long-term survival This capacity is often quantified as the probability of maintaining a specific population level over a designated timeframe.
Sticky, disc-shaped structure at the base of the caudicle Used by an orchid to glue the pollinia to the pollinator.
The Mount Baker-Snoqualmie National Forest, in collaboration with the Washington Natural Heritage Program, developed an initial draft of the Conservation Assessment as part of a Challenge Cost-Share initiative (Potash, 1993) Key contributors to this project included Mark Sheehan, John Gamon, Brandy Reed, Jan Henderson, Robin Lesher, Clayton Antieau, and Thomas Belfield, who assisted with fieldwork and provided valuable feedback on the draft.