Western Blue-eyed Grass
Description (Jepson, PlantID.net)
- 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)
- Basal and alternate (one leaf at each junction with stem)
- Grass-like, in fan-like sprays that sheathe the stem
- 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)
- 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
- 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
- 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
- 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
- Found in moist grasslands
- See iNaturalist for observations of this plant
- Flowers March – May
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.