strict blue-eyed grass

Strict blue-eyed grass is a common prairie wildflower. It is native to the northern and south-central United States and most of Canada. It was introduced in France, probably during the First World War. It is now naturalized throughout most of Europe. In the U.S., it is found in moist meadows and open woodlands and on stream banks. It grows under full sun in loamy soil. It often forms clumps.

Strict blue-eyed grass is a 4″ to 20″ (10 to 50 cm) tall, erect, perennial forb that rises on 2 to 6 basal leaves and one or more aerial stems from fibrous roots. It there are underground horizontal stems (rhizomes), they are barely discernible or obscure.

There is some disagreement in the literature about the presence of a waxy film (glaucous) on the stems and leaves. According to Flora of North America, the plant is “not glaucous.” According to Gleason & Cronquist (1992), the plant is “glaucescent”, meaning becoming glaucous. According to Michigan Flora (Voss, 1972) the plant is “with a more glaucous aspect.” According to Minnesota Flora (Chadde, 2019), the plant is “waxy”.

The leaves are mostly from the base of the plant (basal), but one or more may arise low on the stem. The leaf blade is grass-like (linear), narrow, hairless, and 1⁄16″ to ⅛″ (1.5 to 3.0 mm) wide, almost as long and wide as the stem.

The aerial stem is unbranched, flattened, obviously winged, hairless, and 1⁄16″ to ⅛″ (2.0 to 3.7 mm) wide. The margins in western populations are toothed near the top, but in eastern populations they are not toothed.

The inflorescence is a single flower or a single, unstalked, flattened, fan-shaped cluster (cyme) of 2 to 11 flowers at the end of the stem. The cyme is subtended by and partially enclosed by a pair of claw-like bracts. Together the bracts are called a spathe, and each bract is called a spathe.

The spathes are hairless, folded (keeled), and usually green or bronze. They rarely have purplish margins. The keel usually has very small teeth. The outer spathe is 1 7⁄16″ to 3″ (36 to 76 mm) long. It is always 9⁄16″ to 1 13⁄16″ (14 to 46 mm) longer than the inner spathe, and it is usually at least ⅝″ (16 mm) longer. It is folded lengthwise and fused at the base for 1⁄32″ to ⅛″ (1.0 to 3.5 mm), partially enclosing the base in the inner spathe. The inner spathe has very thin, 1⁄256″ to 3⁄256″ (0.1 to 0.3 mm) wide, membranous, translucent margins from the base to 1⁄32″ to 5⁄32″ (0.9 to 4.3 mm) from the tip, which is green. The margin of the outer spathe is distinct all the way to the base.

The flowers are about ¾″ (20 mm) in diameter. They are at the end of a slender, hairless, ¾″ to 1″ (2.0 to 2.5 mm) long stalk. They are drooping when in bud, becoming erect when in flower. Each flower has 3 petals, 3 petal-like sepals (6 tepals), 3 stamens, and 3 styles. The tepals are widely spreading, inversely lance-shaped, and ⅜″ to 9⁄16″ (9.0 to 14.5 mm) long. They are notched at the rounded tip, and they have a bristle-like extension at the tip. They are usually dark bluish violet, sometimes blue, and they are yellow at the base. The stamens have white filaments and yellow anthers. The filaments are fused for most of their length around the styles. The styles extend between the filaments and beyond the anthers.

The fruit is a tan to dark brown, ⅛″ to ¼″ (4 to 6.8 mm) long, globe-shaped to inversely egg-shaped capsule containing many seeds. It is sometimes tinged purple at the tip. It is erect to spreading at the end of a stalk (pedicel).

4″ to 20″ (10 to 50 cm)

Usually dark bluish violet, rarely blue, and yellow at the base

Prairie blue-eyed grass (Sisyrinchium campestre) flowers are usually pale violet or light blue, sometimes white.

Dry to moderate moisture. Moist meadows, open woodlands, and stream banks. Full sun. Loamy soil.

May to July

Sources

2, 3, 4, 5, 7, 24, 28, 29, 30.

Native

Common

There are two recognized varieties of Sisyrinchium montanum: S. m. montanum, common and widespread across the northern United States and southern Canada; and S. m. crebrum, restricted to the northeast. USDA PLANTS and NatureServe show S. m. crebrum as native to Minnesota. However, there are no records of it in the state, and the Minnesota DNR (MNTAXA) does not list it for the state.

Blue-eyed Grass...

Shows somewhat how small the flowers are when it blooms.… It seems to be blooming a lot now and I seen many little purplish flowers, but they all looked so similar and none much different than any other.

Wild Iris Sisyrinchium montanum var montanum
Rocky Mountain Biological Lab Videos

Mountain Blue-eyed Grass Wildflowers ~ Sisyrinchium montanum
The Snowflake Photographer

Dan W. Andree
Spring 2024

Location: SNA in Norman Co. Mn.

Shows somewhat how small the flowers are when it blooms.… It seems to be blooming a lot now and I seen many little purplish flowers, but they all looked so similar and none much different than any other.