Iris family (Iridaceae)
Description: This perennial plant is ½–1' tall, consisting of a tuft of basal leaves and flowering stalks that are grass-like in appearance. The basal leaves are shorter than the flowering stalks; they are both green, linear, and about 1/8" across. Each flowering stalk is narrowly winged and terminates in a pair of flower-bearing spathes and an outer leafy bract. Each spathe is sessile and consists of a pair of claw-like bracts up to 1" long; these bracts are often reddish or light brownish green. The outer leafy bract is up to 3" long. Between the bracts of each spathe, there develops a floppy umbel of flowers. Although an umbel has up to 6 flowers, only 1 or 2 flowers bloom at the same time. When it is fully open, each flower is about ½" across and consists of 6 white or pale blue tepals, a united column of yellow to orange-yellow stamens, and a green globoid ovary that is covered with fine glandular hairs. The slender pedicel of each flower is about ½" long. The blooming period occurs from late spring to early summer and lasts about 3-4 weeks; the flowers usually remain open from late morning to mid-afternoon on sunny days. There is no noticeable floral scent. Each flower is replaced by a seed capsule that is globoid and ridged; this capsule eventually turns brown and contains many small seeds. The root system consists of a tuft of coarse fibrous roots. This plant spreads by forming offsets and by reseeding itself.
Cultivation: The preference is full sun, mesic levels of moisture, and a loamy soil, although this species will adapt to other growing conditions. It often adapts well to grassy areas, but dislikes competition from taller broad-leaved forbs.
Range & Habitat: The native White Blue-Eyed Grass is occasional to locally common in most areas of Illinois; it is somewhat less common in the western half of the state (see Distribution Map). Habitats include mesic prairies, savannas, meadows in wooded areas, open woodlands, limestone glades, and grassy areas along railroads. This species can be found in degraded meadows with Kentucky Bluegrass, as well as higher quality prairies with native bunch grasses. Occasional wildfires are probably beneficial in preventing this species from becoming smothered by the decaying remains of taller vegetation.
Faunal Associations: Various kinds of bees and flower flies visit the flowers for nectar or pollen; the bees are probably more effective at cross-pollination. I have observed a small dark beetle gnawing on the flowers; it remains unidentified. Little else is known about floral-faunal relationships for this species.
Photographic Location: The webmaster's wildflower garden in Urbana, Illinois. In one photograph, a long leafy bract lies above the spathes. The bracts of the outer spathe are readily observable, while the bracts of the inner spathe are emerging from the leafy bract.
Comments: This is one of the more common Sisyrinchium sp. in Illinois. White Blue-Eyed Grass can be rather variable in appearance: one common form is short (about 6" high) with white flowers, while another form is tall (about 12" high) with pale blue flowers. White Blue-Eyed Grass is the only Sisyrinchium sp. in Illinois with 2 sessile spathes at the apex of each flowering stalk. Only one of the spathes may be evident when a flowering stalk begins to bloom; however, both spathes (each consisting of a pair of claw-like bracts) should be observable later during the blooming period or when the seed capsules develop. Other Sisyrinchium spp. produce a single sessile spathe on each flowering stalk, or they produce spathes on long secondary stalks (peduncles) at least occasionally. Sometimes Sisyrinchium albidum is called Common Blue-Eyed Grass.