Sisyrinchium pallidum
Author: Cholewa & D. Henderson

Pale blue-eyed grass

Iridaceae (iris family)

Close up of Sisyrinchium pallidum by Denise Culver.

Close up of Sisyrinchium pallidum by Allison Shaw.

Taxonomic Comments

Ackerfield (2015) notes that this species may be best represented as a variety of S. montanum.

Ranks and Status

Global rank: G3
State rank: S2
Federal protection status: BLM Sensitive
State protection status: None

Description and Phenology

Sisyrinchium pallidum by Lotus McElfish.

Sisyrinchium pallidum by Carolyn Crawford.

General description: Perennial, herbaceous monocot with grass-like leaves and six pale blue tepals that are yellow at the base. Plants grow to 3 dm, with unbranched stems. Outer tepals are 7-10 mm long. Outer spathe bracts are (18) 28-40 (49) mm long. Inner bracts have a narrow hyaline margin all the way to the tip. The fruits, 2.7 to 6.8 mm long, are tan to dark brown capsules, globose in shape (Cholewa and Henderson 1984, Culver and Lemly 2013, Ackerfield 2015).

Look Alikes: Sisyrinchium montanum and S. idahoense var. occidentale have deep blue flowers. The outer bract of S. idahoense var. occidentale is subequal to the inner bract. Sisyrinchium demissum usually has more than one pedunculate spathe (bract below the inflorescence) arising from the axil of a leaf-like bract on the stem, while S. pallidum has a single sessile spathe (Spackman et al. 1997). It is especially important to note the color of the flowers (pale blue vs. deep blue) when specimens are taken.

Phenology: Flowering occurs from about mid June through July and likely depends on annual growing conditions, especially the availability of water. Mature fruits are present from near the end of June into early August (Hartman 1992).



Habitat of Sisyrinchium pallidum by Susan Panjabi.

Sisyrinchium pallidum occurs in wet meadows often where ample fresh, often standing water is available at least through June or early July. These include stream, lake and river margins up slope from the most hydrophytic sedges and rushes, seep areas down stream from earthen dams, and irrigated hay meadows (Hartman 1992). It grows especially on alkaline soils (Culver and Lemly 2013), often with Juncus arcticus and Carex aquatilis.

Elevation Range: 6,322 - 9,708 feet (1,927 - 2,959 meters)


Colorado endemic: No
Global range: Regional endemic, known from Albany, Carbon and Sweetwater counties in Wyoming and Chaffee, El Paso, Fremont, Gilpin, Jackson, Larimer, Park, Saguache, and Teller counties in Colorado.
State range: Known from Chaffee, El Paso, Fremont, Gilpin, Jackson, Larimer, Park, Saguache and Teller counties in Colorado. Estimated range in Colorado is 18,928 square kilometers (7308 square miles), calculated in 2008 by the Colorado Natural Heritage Program in GIS by drawing a minimum convex polygon around the known occurrences. Also known from Wyoming.
Distribution of Sisyrinchium pallidum in Colorado according to mapped land ownership/management boundaries (CNHP 2015, COMaP v9). City and Arapahoe NF are less than 1%.

Distribution of Sisyrinchium pallidum in Colorado.

Threats and Management Issues

Summary results of an analysis of the status of Sisyrinchium pallidum based on several ranking factors. This species was concluded to be “Moderately Conserved”. From Rondeau et al. 2011.

The primary threat at this time is considered to be alteration of wetland habitat through peat mining and water diversion projects. Often wetlands are drained to facilitate the extraction of peat. Ground water changes could ultimately alter the quality of wetlands favored by S. pallidum and ownership of water rights could permit diversion of surface water. Because of the uncertainty of how changes in the hydrological regime affect the long-term viability of the plants, modification of the wetland hydrology remains a serious threat. It is not known if all of the occurrences are or are not threatened by these activities.


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    • Cholewa, A.F., and D.M. Henderson. 1984. Biosystematics of Sisyrinchium section Bermundiana (Iridaceae) of the Rocky Mountains. Brittonia 36(4):342-363.
    • Colorado Native Plant Society. 1989. Rare plants of Colorado. Rocky Mountain Nature Association, Colorado Native Plant Society, Estes Park, Colorado. 73 pp.
    • Culver, D.R. and J.M. Lemly. 2013. Field Guide to Colorado's Wetland Plants; Identification, Ecology and Conservation. Colorado Natural Heritage Program, Colorado State University, Fort Collins, 694 pp.
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