CPC Plant Profile: Pale Blue-eyed-grass
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Plant Profile

Pale Blue-eyed-grass (Sisyrinchium sarmentosum)

The delicate pale blue eyed grass in flower. Photo Credit: Lois Kemp
Description
  • Global Rank: N/A
  • Legal Status: N/A
  • Family: Iridaceae
  • State: OR, WA
  • Nature Serve ID: 151762
  • Date Inducted in National Collection: 02/25/1988

Contrary to what its common name suggests, the pale blue-eyed grass is not a grass at all. Although its narrow, flat leaves are grass-like, it is a member of the Iris family. Its pale blue (or occasionally white) flowers betray its familial relationship and allow the keen observer to distinguish it from closely related plants, such as Sisyrinchium idahoense and S. angustifolium. William Suksdorf collected specimens of this plant from the southern Washington Cascade Mountains in 1893. For nearly a century following his collection, little attention was paid to the two dozen populations of pale blue-eyed grass in Oregon, Washington and British Columbia. Douglass Henderson's genetic research in the 1970's indicated that this is a "good" species (in other words, it is genetically and morphologically unique enough to be considered a separate species). This status, as well as its small populations and limited range, contributed to its listing as a Federal Species of Concern. The U.S. Forest Service and The Berry Botanic Garden have worked together since 1995 to study pale blue-eyed grass, focusing on the impacts of cattle grazing and noxious weeds in the Gifford Pinchot National Forest in Washington. We have learned that cattle seek out this plant and eat the leaves, flowers and fruits, virtually eliminating seed production even when only "lightly grazed" (25 head of cattle at the site, grazing for three months). When under this stress, plants reproduce through the production of rhizomes and are able to persist. Under these conditions, however, there is little opportunity to increase genetic variability and a large population of clones will not ensure the survival of the species, as they will be ill equipped to adapt to changing conditions. Other threats to this lovely plant include sheep and other domestic livestock grazing, changes in hydrology (especially changes resulting from road building and other human activities), recreation (camping and off-road vehicle use), and interspecific competition (including natural succession).

Participating Institutions
Updates
  • 09/29/2020
  • Demographic Research

Monitoring at Little Crater Meadow: Six transects were laid out during summer of 1990 with the intention of comparing grazed vs. ungrazed areas. Attempts to compare grazed and ungrazed areas were complicated by the failure of fences to keep cattle off plots in 1991, changes in grazing patterns so that only one plot was consistently grazed between 1991 and 1993, and yearly changes in phenology in response to weather. No strong conclusions could be drawn, but there was a slight trend indicating that from 1990 to 1993 the whole population increased in numbers but the grazed transect showed less growth. Plant numbers in the grazed plot declined, compared to increasing numbers in the plot that only received light spring grazing and more intense fall grazing. This suggests that early spring grazing may be especially detrimental to pale blue-eyed grass (Gamon 1991). A five-year study examining the fates of marked 'individuals' at the Cave Creek Wildlife Special Area, Gifford Pinchot National Forest, Washington. Plants inside and outside a fence exclosure were monitored from 1996-2000 both before and after yearly cattle introduction. Plants outside the exclosure (those subjected to grazing) showed greater amounts of herbivory on leaves and flowering stalks. Grazed plants produced far fewer flowers and fruits than ungrazed plants. Grazed plants had a greater number of leaf bases than ungrazed plants, suggesting that in the absence of sexual reproduction, asexual reproduction maintains population numbers (Raven, 2001). Noxious weed monitoring at the Cave Creek Wildlife Special Area. The densities of thistle (Cirsium spp.) and tansy ragwort (Senecio jacobiae) are being studied both inside and outside the fenced exclosure (Raven 2001). An observed increase in weed density may threaten the survival of S. sarmentosum.

  • 09/29/2020
  • Tissue Culture

Researchers at the Center for the Reproduction of Endangered Wildlife at the Cincinnati Zoo and Botanical Garden developed germination and propagation protocols for pale blue-eyed grass, including the specific tissue culture methods (Berry Botanic Garden file).

  • 09/29/2020
  • Reproductive Research

Pollination observations revealed that the pollinators do not distinguish between Sisyrinchium sarmentosum and S. idahoense. Hybrids have been shown to have some but limited viability (Karst, pers. comm.). Controlled artificial hybridization experiments, analysis of breeding systems, and cytological investigations (Henderson 1976). A five-year study examining the fates of marked 'individuals' at the Cave Creek Wildlife Special Area, Gifford Pinchot National Forest, Washington. Plants inside and outside a fence exclosure were monitored from 1996-2000 both before and after yearly cattle introduction. Plants outside the exclosure (those subjected to grazing) showed greater amounts of herbivory on leaves and flowering stalks. Grazed plants produced far fewer flowers and fruits than ungrazed plants. Grazed plants had a greater number of leaf bases than ungrazed plants, suggesting that in the absence of sexual reproduction, asexual reproduction maintains population numbers (Raven, 2001).

  • 09/29/2020
  • Genetic Research

Genetic analysis of S. sarmentosum populations in Oregon and Washington using RAPD markers (Random Amplified Polymorphic DNA). Populations are clustered into three main regions depending on how related they are genetically (1 grouping in Washington and 2 groupings in Oregon). All three of the largest Washington populations are closely allied. They share a watershed, and presumably there is some gene flow between the three populations. The two largest Oregon populations are different genetically. All of the smaller populations analyzed either fall within one of the three genetic groups, or are very different genetically due to hybridization with S. idahoense (Karst, pers. comm.). Pollination observations revealed that the pollinators do not distinguish between Sisyrinchium sarmentosum and S. idahoense. Hybrids have been shown to have some but limited viability (Karst, pers. comm.).

  • 09/29/2020
  • Propagation Research

Researchers at the Center for the Reproduction of Endangered Wildlife at the Cincinnati Zoo and Botanical Garden developed germination and propagation protocols for pale blue-eyed grass, including the specific tissue culture methods (Berry Botanic Garden file).

  • 09/29/2020
  • Propagation Research

Germination trials achieved 60% germination when seeds were subjected to 8 weeks of cold stratification followed by alternating 50F/68F (10/20C) temperatures. 40% of the seeds germinated when cold stratified and subjected to constant 68C (20C) temperatures. No seeds germinated when seeds were placed directly in a 20C germination chamber, but 40% of the seeds germinated when subjected to only alternating 10C/20C temperatures. This may suggest that seeds must be exposed to cold temperatures (i.e.. at least 50F (10C)) for germination to occur (Berry Botanic Garden file).

Nature Serve Biotics
  • 05/02/2017

Endemic to a small area of the Cascade Mountains in south-central Washington and adjacent northern Oregon. Approximately 19 occurrences are believed extant, with at least five containing over 1000 individuals. Most occurrences are on U.S. Forest Service land. Major threats are cattle grazing, successional encroachment in the absence of natural disturbance, and competition from invasive weeds, with other threats including recreational vehicle use, hybridization with S. idahoense, hydrological changes, timber harvesting, and (possibly) disking/mowing.

Edward Guerrant, Ph.D.
  • 01/01/2010

Cattle grazing, which greatly reduces sexual reproduction, can, over time, decrease genetic diversity of the population (Raven 2001). Changes in hydrology (Gamon 1991). Interspecific competition from noxious weeds and invading trees and shrubs. Comp

Edward Guerrant, Ph.D.
  • 01/01/2010

As of 1999: 6 occurrences in Oregon, 16 in Washington. Populations range in size from as few as 15 individuals to the largest site, with approximately 10,000 individuals (ONHDB and WNHP 2000; Raven 2001).

Edward Guerrant, Ph.D.
  • 01/01/2010

Controlled artificial hybridization experiments, analysis of breeding systems, and cytological investigations (Henderson 1976). Monitoring at Little Crater Meadow: Six transects were laid out during summer of 1990 with the intention of comparing grazed vs. ungrazed areas. Attempts to compare grazed and ungrazed areas were complicated by the failure of fences to keep cattle off plots in 1991, changes in grazing patterns so that only one plot was consistently grazed between 1991 and 1993, and yearly changes in phenology in response to weather. No strong conclusions could be drawn, but there was a slight trend indicating that from 1990 to 1993 the whole population increased in numbers but the grazed transect showed less growth. Plant numbers in the grazed plot declined, compared to increasing numbers in the plot that only received light spring grazing and more intense fall grazing. This suggests that early spring grazing may be especially detrimental to pale blue-eyed grass (Gamon 1991). A five-year study examining the fates of marked 'individuals' at the Cave Creek Wildlife Special Area, Gifford Pinchot National Forest, Washington. Plants inside and outside a fence exclosure were monitored from 1996-2000 both before and after yearly cattle introduction. Plants outside the exclosure (those subjected to grazing) showed greater amounts of herbivory on leaves and flowering stalks. Grazed plants produced far fewer flowers and fruits than ungrazed plants. Grazed plants had a greater number of leaf bases than ungrazed plants, suggesting that in the absence of sexual reproduction, asexual reproduction maintains population numbers (Raven, 2001). Noxious weed monitoring at the Cave Creek Wildlife Special Area. The densities of thistle (Cirsium spp.) and tansy ragwort (Senecio jacobiae) are being studied both inside and outside the fenced exclosure (Raven 2001). An observed increase in weed density may threaten the survival of S. sarmentosum. Genetic analysis of S. sarmentosum populations in Oregon and Washington using RAPD markers (Random Amplified Polymorphic DNA). Populations are clustered into three main regions depending on how related they are genetically (1 grouping in Washington and 2 groupings in Oregon). All three of the largest Washington populations are closely allied. They share a watershed, and presumably there is some gene flow between the three populations. The two largest Oregon populations are different genetically. All of the smaller populations analyzed either fall within one of the three genetic groups, or are very different genetically due to hybridization with S. idahoense (Karst, pers. comm.). Pollination observations revealed that the pollinators do not distinguish between Sisyrinchium sarmentosum and S. idahoense. Hybrids have been shown to have some but limited viability (Karst, pers. comm.). Germination trials achieved 60% germination when seeds were subjected to 8 weeks of cold stratification followed by alternating 50F/68F (10/20C) temperatures. 40% of the seeds germinated when cold stratified and subjected to constant 68C (20C) temperatures. No seeds germinated when seeds were placed directly in a 20C germination chamber, but 40% of the seeds germinated when subjected to only alternating 10C/20C temperatures. This may suggest that seeds must be exposed to cold temperatures (i.e.. at least 50F (10C)) for germination to occur (Berry Botanic Garden file). Researchers at the Center for the Reproduction of Endangered Wildlife at the Cincinnati Zoo and Botanical Garden developed germination and propagation protocols for pale blue-eyed grass, including the specific tissue culture methods (Berry Botanic Garden file).

Edward Guerrant, Ph.D.
  • 01/01/2010

Most existing U.S. populations occur on Forest Service land. Cattle graze most of the Washington populations each year. Cattle are not allowed to graze the Oregon populations. At the Cave Creek Wildlife Special Area in the Gifford Pinchot National Forest in southern Washington, 64 acres have been fenced to exclude cattle grazing since 1994. The fence allows elk, deer and other wildlife access to the area. Plants in this population are located both inside and outside the exclosure (Raven 2001). The Forest Service is performing noxious weed removal through hand pulling, flower removal, and biological control agents (insects that eat only the noxious weed) at several sites (Raven 2001).

Edward Guerrant, Ph.D.
  • 01/01/2010

Field observations suggest that ample seed is produced, but little is known about germination requirements. Little is known about dispersal mechanisms or rates of seedling establishment and survival (Gamon 1991). The small number of occurrences is a concern. All currently known populations should be maintained, even though some are extremely small, because they can safeguard against chance environmental or human-related events (Gamon 1991). Karst (pers. comm.) suggests that it is especially important to protect the large populations in the three centers of diversity (1 in WA, 2 in OR). Small populations may be difficult to preserve. Limit or prevent road and trail construction through existing habitat (Gamon 1991). Recreational use of sites should be discouraged (Gamon 1991). Grazing should be prohibited within any known sites that are not currently part of an allotment. Grazing allotments with population should be monitored regularly (Gamon 1991). Trees and shrubs should be removed where encroachment is a concern (Gamon 1991). Activities associated with timber harvest should be prohibited within known sites. Harvest of adjacent areas should be reviewed by a hydrologist, soil scientist, and a botanist or ecologist familiar with the species (Gamon 1991).

Edward Guerrant, Ph.D.
  • 01/01/2010

Collect and store seeds from as many populations as possible. Determine propagation and reintroduction protocols.

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Photos
Nomenclature
Taxon Sisyrinchium sarmentosum
Authority Suksdorf ex Greene
Family Iridaceae
CPC Number 4016
ITIS 43273
USDA SISA4
Common Names pale blue-eyed grass | mountain blue-eyed grass
Associated Scientific Names Sisyrinchium sarmentosum
Distribution OR, WA, British ColumbiaOR: Western Cascades &Crest (Clackamas Co, Marion Co.) (Mt. Hood National Forest)WA: Eastern Cascades, Western Cascades (Gifford Pinchot National Forest)
State Rank
State State Rank
Oregon S1
Washington S1S2
Habitat

Slightly raised (and therefore slightly drier) sections of open, wet meadows in forest openings, primarily in the Pacific Silver Fir and Grand Fir zones. Elevations range from 1600 to 3920 ft (490-1200 m) in Washington and 2160 to 4000 ft (650-1220 m) in Oregon.

Ecological Relationships

Flowers of northwestern blue-eyed grasses are protandrous (meaning that the male parts of the flower mature before the female parts). This promotes outcrossing and reduces chances of self-pollination in self-compatible plants. Solitary bees (family Megachilidae) facilitate pollination (Henderson 1976). Bumblebees (Bombus spp.) have also been observed visiting the flowers. Flowers do not open until late morning or mid-day (Gamon 1991). Flowering largely depends upon elevation and weather patterns during late spring and early summer. Lower elevations (ca 2000 ft or 600 m) begin flowering in early June and have mature capsules by mid July, while those at higher elevations (3700-4000 ft (1100-1220 m)) begin to flower in mid to late July and have mature capsules around mid-August (Gamon 1991). Sisyrinchium idahoense occurs in a similar habitat (Gamon, 1991) and is found growing along with S. sarmentosum in at least one large site (Karst, pers. comm.). This species is clonal (Gamon 1991) and when heavily grazed, this may be the primary means that the plant reproduces itself. Sisyrinchium sarmentosum's associated species include Deschampsia cespitosa, Alopecurus pratensis, Phleum pretense, Poa palustris, Juncus tenuis Juncus ensifolius, Carex vesicaria, Carex microptera, Agrostis idahoensis, Fragaria virginiana var. platypetala, Prunella vulgaris, Trifolium repens, Potentilla drummondii, Ranunculus flammula, Solidago canadensis, Veronica scutellata, Botrychium multifidum, Antennaria microphylla and Viola adunca (Gamon 1991). Common associated shrubs and trees include Spirea douglasii, Pinus contorta, Picea engelmannii, Acer circinatum and Populus trichocarpa (Gamon 1991).

Pollinators
Common Name Name in Text Association Type Source InteractionID

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