Blue-eyed Grass

Blue-eyed Grass © SBernhard

Western Blue-eyed Grass
Sisyrinchium bellum

Description (Jepson,

  • Monocotyledon
    • Monocots are a major lineage of flowering plants; see family for general characteristics
  • Iris Family (Iridaceae)
  • Perennial herb, upright growth habit
    • Grows from rhizomes (underground, horizontal stems)
  • Leaves
    • Basal and alternate (one leaf at each junction with stem)
    • Grass-like, in fan-like sprays that sheathe the stem
  • Flowers
    • Inflorescence (flower arrangement) of 3-5 flowers open sequentially on branching iris-like stalks, about the height of the leaves
    • 3 petals and 3 sepals (outer flower parts), similar in appearance and collectively called tepals
      • Blue-purple, with dark lines (nectar guides) leading to a yellow center
      • Outer edge often with a small point (mucro) projecting from a notch
    • 3 stamens (male flower parts), fused in a column around the pistil (female flower part)
    • Ovary inferior (below the attachment of other flower parts)
  • Fruit is a capsule (a dry, multi-chambered fruit that splits open at maturity)
  • Height 12-18 in.


  • Native to California
    • Grows in open grasslands with some moisture, but also found in woodlands
    • See Calflora for statewide observations of this plant
  • Outside of California, grows from Oregon to Mexico, but confined to western North America
  • Grows at elevations to 7,900 ft.

Uses (San Mateo County Parks prohibits removal of any natural material)

  • Wildlife
    • Nectar and pollen source for insects
  • Native people
    • Decoction used to treat chills and stomach aches
    • Purgative produced from roots
    • Infusion of washed roots taken for upset stomach, heartburn, asthma, and ulcers

Name Derivation

  • Sisyrinchium (si-si-RINK-ee-um) from the Greek sys, “pig,” and rynchos, “snout,” alluding to pigs grubbing the roots for food
    • Theophrastus, a student of Aristotle, first used this name to describe a type of iris (Ritter 2018)
  • bellum (BEL-lum) – Latin for handsome
  • Blue-eyed grass – flower suggests a blue eye with a yellow iris; leaves are similar to grass
    • From a distance, a field of blue-eyed grass can appear spotted with blue eyes
    • Also sometimes called yellow-eyed iris
Seeds © DSchiel


  • Flowers open in the morning and close in the evening or when it’s cloudy
    • This process is an example of nyctinasty, which refers to diurnal and nocturnal changes (single or repetitive) exhibited by the leaves and flowers of some plants (van Doorn 2003)
  • After flowering, the plant dies back and remains dormant through the summer
  • The petals and sepals of plants in the blue-eyed grass genus, Sisyrinchium, look more alike than do those of typical garden irises

ID Tips

  • May be confused when not flowering with iris-leaved rush (Juncus xiphioides), which also has sheathing, linear leaves
    • Iris-leaved rush leaves are hollow, and you can feel bumps from the interior partitions (crosswalls) by running your fingers along the leaf blade
  • Check out this short Jepson video for more ID tips

At Edgewood

  • Found in moist grasslands
  • Flowers March – May

See General References

Specific References

Ladybird Johnson Wildflower Center. 2009. Sisyrinchium bellum. Plant Database. University of Texas at Austin.

Nature Collective. 2020. Blue-eyed grass.

Ritter, M. 2018. California Plants: A Guide to Our Iconic Flora. Pacific Street Publishing, San Luis Obispo, California.

van Doorn, W.G. and U. van Meeteren. 2003, Aug. 1. Flower opening and closure: A review. Journal of Experimental Botany 54: 1801–1812. Oxford Academic.