Sisyrinchium idahoense

From Puget Prairie Plants
  • Scientific Name: Sisyrinchium idahoense
  • Family: Iridaceae
  • Common Names: blue-eyed grass, Idaho blue-eyed grass
  • Codon: SISIDA

Photo by Ben Legler, 2004, also featured on Main Page


Scientific classification
Kingdom: Plantae
Subkingdom: Viridiplantae
Phylum: Tracheophyta
Subphylum: Spermatophytina
Class: Magnoliopsida
Subclass: Lilianae
Order: Asparagales
Family: Iridaceae
Genus: Sisyrinchium L.
Species: Sisyrinchium idahoense E.P. Bicknell



Showy, tufted perennial to 40 cm tall; stems usually flattened and wing-margined. Leaves mostly basal, long (to 20 cm.) and very narrow (< 2 mm broad).

Flowers consisting of 6 tepals, blue to purplish-blue with yellow centers. Flowers are small (about 2 cm across) and arranged in a terminal cluster of two to five flowers above a pair of sheathing, leaf-like bracts, emerging much lie irises.

1 prominent pistil and 3 stamens, ovary in inferior and pubescent.

Fruits egg-shaped capsules to 6 mm long, with black seeds [2][3]

Bloom Period

March to June


Both S. i. var. occidentale (outer tepals 8-13 mm, inner spathe 12-20mm; spathe keel margins entire) and S. i. var. segetum (outer tepals 10-17 mm; spathe keel margins generally denticulate) have been reported in the South Salish Sea region. [4][3]


Ecological Setting

Moist to wet grassy meadows, vernal seepage areas, marshes, roadside ditches; at low to middle elevations [2]

Soil Texture

Fine to well-drained.

Soil Reaction / Salinity

Mildly acidic to alkaline (pH 5.5 to 7.5) [5]

Shade Tolerance

Full sun to partial shade [6]

Successional Status

Considered a "weedy" species and a good early secession species after disturbance. [7]


Site Rehabilitation

Possible reclamation species in moister pockets in selected sites [8]


Solitary bees of the family Megachilidae are mainly responsible for cross-pollination in natural populations. [5]


Mass-plant to create a showy display in a border or a rock garden [6]


Seed Propagation

Flowers are protandrous, thereby promoting out-crossing and at the same time reducing the chances for self pollination. S. idahoensis is an octoploid species and often exhibits a lag of up to 24 hours between anther maturation and stigma receptivity [5]

Fruit and Seed Collection and Extraction

Collect capsules by hand when ripe into collecting bags. Allow to dry further and then shake bags to extract seeds [9]

Seed Storage

Cold store at 5º C for up to three years [9]

Sisyrichium idahoense seed. Photo by Lisa Hintz

Fruit/Seed Dormancy and Treatment

Seal seeds in a Ziploc-style bag or a Rubbermaid-style container in equal amounts of seed to perlite or vermiculite, and add just enough water to moisten the mixture. Cold stratify at 5º C for 8 to 12 weeks [9]

Outplanting Characteristics and Requirements

Out-plant in the fall to take advantage of natural moisture or plant in spring and provide supplementary watering. Successfully self-seeds in situ. Can be successfully divided in situ in the spring by simply teasing plants apart and replanting the resulting clumps [10]

Photo Gallery


  1. Integrated Taxonomic Information System. Retrieved from
  2. 2.0 2.1 Pojar and MacKinnon, 1994
  3. 3.0 3.1 Bowcutt, F., & Hamman, Sarah. (2016). Vascular plants of the South Sound prairies (First ed.). Olympia, Washington: The Evergreen State College Press.
  4. Hitchcock, C. L., Cronquist, A., Giblin, D., & Legler, B. et al. (2018). Flora of the Pacific Northwest: an illustrated manual. Seattle: University of Washington Press.
  5. 5.0 5.1 5.2 Henderson, 1976
  6. 6.0 6.1 Tenenbaum et al., 1994
  7. Alverson, 2002
  8. Winters, 2002
  9. 9.0 9.1 9.2 Schultz et al., 2001
  10. R. Bridgeman, pers. comm.