The following Participating Institutions are custodians for this species in the CPC National Collection:
Rae Selling Berry Seed Bank & Plant Conservation Programs
University Of Washington Botanic Gardens
The conservation of Polemonium pectinatum is fully sponsored.
Edward Guerrant, Ph.D. contributed to this Plant Profile.
According to the Endangered Species Act, rare plants found on private land are not required to receive specialized protection. Landowners are not required preserve an endangered plant's habitat. This is cause of concern for Polemonium pectinatum, an herbaceous perennial endemic to eastern Washington. Of the 35 extant occurrences, 25 are found on private land (Gilbert 1998). Polemonium pectinatum is considered a Species of Concern by the U.S. Fish and Wildlife Service and is listed as Threatened by the state of Washington. Even if this species were listed as Threatened or Endangered under the Endangered Species Act, only 10 populations would be officially protected by law.
The unique and starkly beautiful scabland habitat is under continued threat from agricultural conversion and urban development, and consequently so is Polemonium pectinatum. Only by combining the efforts of the federal government, conservation organizations, and most importantly, the local landowners, can the future of this rare and beautiful plant be ensured.
Distribution & Occurrence
Polemonium pectinatum grows along creek terraces, mid-slope depressions, the banks of seasonal creeks, and coulee floors in the arid to semi-arid shrub-steppe zone of eastern Washington at elevations of 1500 to 2300 ft (460-700 m). Associated species include Crataegus douglasii, Amelanchier alnifolia, Elymus cinereus, Rosa woodsii, and Ribes aureum.
|An estimated 18,000 total individuals in 35 occurrences. 25 occurrences are on private land, 9 are on Bureau of Land Management (BLM) land and 1 is on a railroad right-of-way managed by the Washington Department of Natural Resources. The 9 BLM occurrences account for an estimated 8,000-10,000 individuals, half of the total (WNHP 1999). Populations range in size from as few as 3 to more than 2000 (WNHP 1999).|
Conservation, Ecology & Research
In a recent study of habitat requirements and general ecology, half of the stands dominated by Polemonium pectinatum contained 20% or greater cover of Senecio serra and Elymus cinereus (Gilbert 1998). Soil chemistry varied greatly between suitable Polemonium pectinatum habitat and adjacent habitat within a given site. Total carbon and total nitrogen were higher for P. pectinatum sites than for sites not containing P. pectinatum. The observed levels of calcium, magnesium and sodium were lower in P. pectinatum habitat than in most areas with low rainfall (Gilbert, 1998). The soil was often covered by a fairly deep litter layer, accompanied by high microorganism activity and high carbon input into the soil. Seasonal flooding occurs in the habitat area, making it necessary for P. pectinatum to be able to withstand anaerobic (no oxygen) conditions (Gilbert 1998).
Germination percentage of seed in the wild is extremely low. While between 52% and 66% of the seeds were viable in one experiment, germination rates were between 1% and 6.2% depending on year and depth buried. Fresh seeds seem to require a long soak in water and a period of cold stratification. When 3-week old seed was planted in the greenhouse, 0-5% of the seeds germinated. After soaking in water for 24 hours, the germination percentage was up to 63%. Germination percentages were as high as 79% for seeds subjected to 3 weeks of chilling after being soaked in water (Gilbert 1998). High soil moisture levels in the wild are critical to successful germination.
Presumably, plants are self-compatible. No formal experiments have been done, but a single individual in a garden setting can produce seeds, and plants grown in a greenhouse setting (where pollinators are excluded) set seed as well (Gilbert 1998).
Grazing (WNHP 1999).
Habitat domination by non-native weeds (Gilbert 1998).
Hydrology changes (depth to groundwater) due to wells, pumping from creeks, and creek channelization and divers
Demographic monitoring. Data on population structure, seed production, seed germination, and plant survival and growth were analyzed using a transition matrix model to study population dynamics. The effect of herbicide spraying and weed pulling was analyzed (Gilbert 1998).
Genetic analysis utilizing isozymes (protein analysis) and microsatellites (SSR). Little to no variation was found using isozyme markers. Results from microsatellite analysis suggests that inbreeding may be occurring at all sampled locations (Gilbert 1998).
Germination studies using 3 week-old seed indicate that a period of moist, cold stratification is required for successful germination (Gilbert 1998).
Germination studies using old seed (over 5 years old) were conducted at The Berry Botanic Garden. One set of seeds was subjected to 8 weeks of cold stratification followed by placement in either constant 68F (20C) or alternating 50/68F (10/20C). Another set was not cold stratified before placement in the two different temperature regimes. 60% of seeds that were cold stratified germinated, regardless of temperature regime. 100% of seeds that were not cold stratified germinated, regardless of temperature regime (BBG File).
Evaluation of genetic diversity between populations of Polemonium pectinatum. Researchers found high allelic diversity for 6 polymorphic loci. They also found that heterozygosity and within population variation were not near Hardy-Weinberg equilibrium (Gilbert 2001), indicating that inbreeding may be occurring.
Development of a "Conservation Strategy" (Gilbert 1998).
Proposed re-introduction near Pine Creek or Rock Creek sites (Gilbert 1998).
A portion of Bureau of Land Management (BLM) land has been designated as an Area of Critical Ecological Concern (ACEC). Polemonium pectinatum habitat is protected in the ACEC. Prior to being designated as an ACEC, grazing was allowed on the land (in Gilbert 1998).
Stream bank stabilization within the ACEC (Pam Camp, BLM in Gilbert 1998).
Selective herbicide treatments to destroy invasive weeds within the ACEC (Pam Camp, BLM in Gilbert 1998).
Study effect of flooding on Polemonium pectinatum (WNHP 1999).
Study potential deleterious effects of inbreeding on short-term population vigor (Gilbert 2001) .
Demographic monitoring of grazed and ungrazed areas (Gilbert 1998).
Federal agencies and conservation groups should work to obtain permission from private landowners to manage Polemonium pectinatum populations, as many populations are on private land.
Quantify how dry conditions, weeds, and grazing effect populations (Gilbert 1998).
Analyze breeding system (Gilbert 1998).
Determine propagation and reintroduction protocols.
Gilbert, C. 2001. Genetic Variation and the Conservation of Polemonium pectinatum (Polemoniaceae). In: Reichard, S.H.; Dunwiddie, P.W.; Gamon, J.G.; Kruckeberg, A.R.; Salstrom, D.L., editors. Conservation of Washington's native plants and ecosystems. Wash