The Friends of the Wildflower Garden, Inc.

Plants of the Eloise Butler Wildflower Garden

The oldest public wildflower garden in the United States

Blue-eyed Grass

Common Name
Narrowleaf Blue-eyed Grass (Stout Blue-eyed Grass, Pointed Blue-eyed Grass)


Scientific Name
Sisyrinchium angustifolium Mill.


Plant Family
Iris (Iridaceae)

Garden Location
Historical - not extant


Prime Season
Early Summer Flowering



Blue-eyed Grass is a short perennial grass-like forb, growing only up to 12 inches high.

Basal leaves emerge from the root system and resemble the leaves of the common iris plants except that these are very narrow, up to 1/16 inch wide, linear with parallel veins, not round like a true grass. The edges may have very minute serrations. Blade color often looks bluish in sunlight.

Flowering stalks develop among the leaves, reaching to leaf height or slightly higher. Stalks are winged and may branch, having one to two nodes. The stalk ends with a bract, (leaf-like development). From this bract a green spathe (a leaf-like form that envelopes the flowers) forms and from within the spathe comes an umbel of flowers. In this species there is only one spathe per flowering stem. Beneath the umbel, but within the spathe, develop two small bracts, one longer than the other.

The flowers are only 1/2 inch wide and have 3 petals and 3 sepals, which perform the same functions and are known as tepals. These are identically colored - blue to bluish-purple, each ending with a small point at the tip. These lobes are widest above the center and taper to a narrow base which has a yellow splotch. The tepals have a darker veining which acts as a nectar guide for insects. The center of the flower where the sexual parts are is yellow. The stamens are symmetrically arranged around the base and have yellow anthers. These closely surround the 3 styles but are not appressed to them.

Seed: Fertile flowers produce a globose 3-celled seed capsule that is dull brown to blackish, sometimes with purple tinges. This splits into 3 sections when mature to release small black seeds 0.5 to 1.2 mm long. Seeds require 60 days of cold stratification and cool soil for germination. Best to plant in the fall and let nature to the work.


Habitat: Blue-eyed grass grows in moist meadows, riparian edges, moist open woods - wet-mesic to dry-mesic conditions. A high organic content and full to partial sun is needed. It grows from a fibrous root system which can form clumps. Separation of the roots is a good way to increase the number of plants. Even though it is in the Iris family, it fits in well with ornamental grasses.

Names: The genus Sisyrinchium is an old Greek name for another plant that has been adopted for the group of blue-eyed grasses. The species, angustifolium, is from the Latin for 'narrow leaves' although this species actually has leaves broader than than its relatives. The author name for the plant classification - "Mill." is for Philip Miller, Scottish botanist (1691-1771) who was chief gardener at the Chelsea Physic Garden and wrote "The Gardener's Dictionary".

Comparisons: The more commonly found species of Sisyrinchium in Minnesota are: S. campestre, Field Blue-eyed grass; S. montanum, Mountain Blue-eyed Grass; and S. mucronatum, Pointed-petal Blue-eyed Grass. Flowers and spathes must be examined to determine the correct species but S. montanum usually has an unbranched stem.

See bottom of page for notes on the Garden's planting history, distribution in Minnesota and North America, lore and other references.

Plant Drawing

Above: A fine clump of Sisyrinchium angustifolium. Drawing from Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York.

Below: The darker veining of the tepals acts as a nectar guide. Flowers emerge from the spathe that envelops the stem. Note the small bracts also emerging from the spathe- one shorter, below the flower and one longer rising above the flowers.

Flower flower

Below 1st photo - The last flower of this umbel. 2nd photo - a new spathe forming. In both photos you can see the long bract - from which the spathe develops - that forms atop the flowering stem. 3rd photo - The seed capsule in immature state.

sheath stem seed capsule


Notes: Narrowleaf Blue-eyed grass is listed as native to Minnesota on the DNR Plant Survey (2019), but according to the University of Minnesota Herbarium is known only from St. Louis County, was last collected in 1950 and was probable brought in. On April 26, 1908, Eloise Butler noted finding the plant in the Garden and planting a clump on June 1, 1914 obtained from Columbia Heights, MN and again in 1915, '16, '17 and '19, all from local sources. She also noted on June 7, 1920 planting a white flowered specimen; more plants came in 1922, '24, '25, and '29'. As there are two other species of the grass that are found in Hennepin County where the Garden is located, she may have mis-identified the species. Nevertheless, Curator Martha Crone planted the species in 1933 from a source in Anoka and noted it blooming in her 1938 and 1939 log; additional plants in 1945, '46, '48, '50, and '51. So it seems evident both curators mis-identified the species as it is unlikely that Herbarium collections would not have included such a prevalent species. However, the authors of Flora of North America state that in previous work, S. angustifolium was often confused with S. montanum, Strict (or Mountain) Blue-eyed Grass and that a number of authors have lumped the two together. S. montanum has been collected in Hennepin County.

Narrowleaf Blue-eyed grass is native to the eastern half of the United States with Minnesota being on the NW corner of the range. It is also found in Canada in Ontario, Quebec, Labrador and Newfoundland.

References and site links

References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.

graphicIdentification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.