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Home/Species/ Western Ladies'-tresses

Spiranthes porrifolia

Lindl.

Western Ladies'-tresses

G4Apparently Secure Found in 23 roadless areas NatureServe Explorer →
G4Apparently SecureGlobal Rank
MediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.153726
Element CodePMORC2B0T0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
CITESAppendix II
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderOrchidales
FamilyOrchidaceae
GenusSpiranthes
Synonyms
Spiranthes romanzoffiana var. porrifolia(Lindl.) Ames & Correll
Other Common Names
Creamy Ladies'-tresses (EN) creamy lady's tresses (EN)
Concept Reference
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Taxonomic Comments
Hybridization between Spiranthes porrifolia and S. romanzoffiana seems to be rare or absent (Pace and Cameron 2019).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-02-07
Change Date1994-09-23
Edition Date2025-02-07
Edition AuthorsRusso, Mary (TNC WRO, 1989), revised C. Nordman (2025).
Threat ImpactMedium
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences81 - 300
Rank Reasons
Western Ladies'-tresses (Spiranthes porrifolia) occurs in the western United States, in California, Oregon, Washington and Idaho. It is estimated that there are between 81 and 300 occurrences rangewide. The total population size is not well documented. Residential development and urbanization, and the associated loss of wetlands is a threat. This orchid has been documented on Yosemite National Park, Sequoia National Park, Modoc, Mt. Hood, Sequoia, Shasta-Trinity, Sierra, and Tahoe National Forests, Fort Hunter Liggett Military Reservation, Swasey Recreational Area (BLM), City of Chico's Upper Bidwell Park, and California's Washoe Meadows State Park.
Range Extent Comments
Western Ladies'-tresses (Spiranthes porrifolia) occurs in the western United States, in California, Oregon, Washington and Idaho. Range extent was estimated to be about 760000 square kilometers, using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1994 and 2025 (CCH2 2025, GBIF 2025, iNaturalist 2025, NatureServe 2025, Sheviak and Brown 2020). Pace and Cameron (2023 in Jepson Flora Project 2025) do not include Idaho within its range.
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are about 200 (and between 81 and 300) occurrences rangewide (GBIF 2025, iNaturalist 2025, NatureServe 2025, CCH2 2025).
Threat Impact Comments
Residential development and urbanization, and the associated loss of wetlands is a threat.
Ecology & Habitat

Habitat

This species are found in moist to wet stream banks and riparian meadows, seeping banks, freshwater marshes, seeps, fens, and wet roadsides, sometimes occurring over serpentine or granite, at elevations range from 100 to 2700 meters (CCH2 2025, Pace and Cameron 2023 in Jepson Flora Project 2025, Sheviak and Brown 2020).

Reproduction

Hybridization between Spiranthes porrifolia and S. romanzoffiana seems to be rare or absent (Pace and Cameron 2019).
Terrestrial Habitats
Grassland/herbaceous
Palustrine Habitats
HERBACEOUS WETLANDBog/fenRiparian
Other Nations (1)
United StatesN4
ProvinceRankNative
CaliforniaSNRYes
WashingtonS2Yes
OregonS4Yes
NevadaS2Yes
IdahoS1Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentRestricted (11-30%)Serious or 31-70% pop. declineHigh (continuing)
1.1 - Housing & urban areasRestricted (11-30%)Serious or 31-70% pop. declineHigh (continuing)

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (23)
California (20)
AreaForestAcres
BackboneShasta-Trinity National Forest11,466
Big Butte ShinboneMendocino National Forest4,265
BlackKlamath National Forest6,530
Bonanza KingShasta-Trinity National Forest16,402
Castle Crags AShasta-Trinity National Forest113
Castle Crags BShasta-Trinity National Forest1,619
Chips CreekLassen National Forest29,089
Cow CreekShasta-Trinity National Forest22,627
East GirardShasta-Trinity National Forest27,894
Kettle Mtn.Shasta-Trinity National Forest4,589
MayfieldLassen National Forest14,444
North LakeInyo National Forest2,406
Orleans Mtn. CSix Rivers National Forest15,589
PattisonShasta-Trinity National Forest29,299
Salt SpringsEldorado National Forest133
San JoaquinSierra National Forest22,474
SiskiyouKlamath National Forest54,039
Table Mtn.Inyo National Forest4,215
West GirardShasta-Trinity National Forest37,516
Wilderness ContiguousMendocino National Forest3,606
Oregon (3)
AreaForestAcres
North KalmiopsisSiskiyou National Forests91,560
Shasta CostaSiskiyou National Forests14,420
South KalmiopsisSiskiyou National Forests104,477
References (10)
  1. CCH2 Portal. 2025. Consortium of California Herbaria. Online. Available: https//:www.cch2.org/portal/index.php (Accessed 2025).
  2. Flora of North America Editorial Committee (FNA). 2002a. Flora of North America north of Mexico. Vol. 26. Magnoliophyta: Liliidae: Liliales and Orchidales. Oxford Univ. Press, New York. xxvi + 723 pp.
  3. Global Biodiversity Information Facility (GBIF). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  4. iNaturalist. 2025. Online. Available: https://www.inaturalist.org (accessed 2025).
  5. Jepson Flora Project (eds.) 2025. Jepson eFlora. Online. Available: https://ucjeps.berkeley.edu/eflora/ (accessed 2025).
  6. Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
  7. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  8. Pace, M.C. 2015. Evolution, species boundaries, and biogeography of <i>Spiranthes</i> (Orchidaceae): Uncoiling Ames’s “most perplexing orchid genus in our flora”. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Botany) at the University of Wisconsin-Madison.
  9. Pace, M.C. and K.M. Cameron. 2019. The evolutionary and systematic significance of hybridization between taxa of <i>Spiranthes</i> (Orchidaceae) in the California Sierra Nevada and Cascade Range. Taxon 68(2): 199-217. https://doi.org/10.1002/tax.12034
  10. Sheviak, C.J. and P.M. Brown. 2020. Flora of North America. <i>Spiranthes porrifolia</i>. Accessed: September 28, 2022. http://floranorthamerica.org/Spiranthes_porrifolia