Common blue-eyed grass, strict blue-eyed grass
Concentrated in the Rocky Mountains and the Great Plains
Between 4 and 20 inches
Open woodland, streamsides, moist meadows; from sea level to 10,000 feet
Linear, narrow, basal, up to 10 inches long and 0.15 inches wide
The grass-like leaves of Sisyrinchium montanum grow only at the base, and number two to six per stem. Leaves have faint lengthwise grooves. Stems are unbranched, hairless, flattened, and winged. The margins of the wings may be finely toothed. Leaf tips are pointed.
Flowers are produced singly or in a cluster of up to five. Flowers are formed of six tepals, yellow at the base, otherwise bluish purple, crossed by a few darker veins. Tepals are tipped by a narrow, inwards-curving projection. The styles and stamens are joined to form a tube at the center, purplish and glandular hairy towards the base. Beneath the flowers are a pair of unequal-length bracts.
Most specimens of sisyrinchium montanum are var montanum; the less common var crebrum is found only in the northeast of the US. The two varieties are distinguished via the relative lengths of the fused section of the margins of the longer of the two subtending bracts (the spathes).