Wild Blue Flax
Linum perenne lewisii
Flax family (Linaceae)
Description: This perennial wildflower is 1–2½' tall, sending up one or more unbranched stems from the base. Depending on environmental conditions, these flowering stems are more or less erect, or they can sprawl across the ground. The stems are gray-green or gray-blue, terete, and hairless. Arranged around each stem, there are dense pseudo-whorls of small leaves. These leaves are are up to 1½" long and less than ¼" across; they are linear-oblong, gray-green or gray-blue, smooth along their margins, and hairless. Each stem terminates in a cyme of about 10 flowers. While the flowers are in the bud stage, the slender branches of the cyme usually droop downward. When a flower blooms, it becomes more erect. Individual flowers are about ¾–1" across, consisting of 5 light to medium blue petals, 5 dull green sepals, 5 stamens with white anthers, and 5 slender styles. The petals are much larger than the sepals; they have dark blue veins that radiate from the center of the flower. Individual sepals are ovate with membranous hairless margins. The blooming period usually occurs during early to mid-summer. The short-lived flowers up open during the early morning and close by noon. After the blooming period, each flower is replaced by a globoid seed capsule. Each capsule contains 10 cells (5 fertile cells and 5 sterile cells) and 10 flattened seeds. The root system consists of a deep taproot. This wildflower reproduces by reseeding itself.
Cultivation: Full sun, dry conditions, and barren soil containing sand, clay, or rocky material provide the best environment for growth and development. Under more moist and fertile conditions, this wildflower may sprawl or succumb to competition from other plants. The pH of the soil should range from mildly acid to alkaline.
Range & Habitat: The non-native Wild Blue Flax rarely naturalizes in Illinois (see Distribution Map). Habitats include roadside embankments, gravelly areas along railroads, and vacant lots where old homesites once existed. This wildflower could probably adapt to dry gravel, hill, and sand prairies, if it was introduced (not that I'm recommending it). Occasionally, this species is cultivated in flower gardens, from where it can escape. Wild Blue Flax is native to the Great Plains and western areas of the United States.
Faunal Relationships: Because this wildflower is introduced, information about its floral-faunal relationships in the Midwest are limited. The flowers are pollinated primarily by small bees and Muscoid flies (Kearns & Inouye, 1994). The bees usually suck nectar, while the flies usually feed on pollen. In the western states, upland gamebirds (e.g., Sage Grouse) and deer mice eat the seeds; it is possible that the Greater Prairie Chicken and Ring-necked Pheasant would eat the seeds in Illinois. While the foliage contains a cyanide-related compound, it is browsed occasionally by hoofed mammalian herbivores (both wild and domestic), including White-tailed Deer and Elk. Apparently, these animals can eat small amounts of the foliage without experiencing significant toxic effects.
Photographic Location: A roadside embankment that was adjacent to a flower garden, where this plant was cultivated near Champaign, Illinois.
Comments: Wild Blue Flax has very pretty flowers, although they are rather short-lived. While its stems appear to be slender and fragile, they are actually rather fibrous and tough; their fibers were used for various purposes by Amerindians. In this genus, Linum spp. that are native to Illinois have yellow flowers. Like Wild Blue Flax, they usually prefer sunny dry habitats with barren soil. Another introduced flax with blue flowers, Linum usitatissimum (Cultivated Flax), is an annual that is native to Eurasia or the Middle East. This latter species has been cultivated for its fibers for thousands of years; it is the source of linen cloth. Unlike Wild Blue Flax, the sepals of Cultivated Flax have acutely pointed tips; the inner sepals also have ciliate margins.