Linum lewisii (Blue Flax)
|Also known as:||Lewis Flax|
|Origin:||Western North America|
|Habitat:||sun; dry; open prairie|
|Bloom season:||June - July|
|Plant height:||12 to 30 inches|
|Wetland Indicator Status:||none|
|MN county distribution (click map to enlarge):|
|National distribution (click map to enlarge):|
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Drooping panicle of stalked flowers at the tips of branching stems. Flowers are ¾ to 1 inch across, bright blue to blue-violet or occasionally white, with deeper blue radiating from the center, 5 spreading, broadly oval to wedge-shaped petals, widest above the middle, the tips rounded to nearly straight across. The yellow center has 5 styles that are about as long as or longer than the 5 white-tipped stamens.
The 5 sepals are lance-elliptic, hairless, and green with a papery translucent edging. Flower stalks are slender and smooth, about ½ inch long, drooping in bud, becoming erect at flowering and may droop again in fruit. Flowers open in early morning and usually close by noon.
Leaves and stems:
Leaves are erect to ascending, alternate but appearing whorled on the lower stem, 1/3 to about 1 inch long, less than ¼ inch wide, lance-linear, pointed or blunt at the tip, 1-nerved, stalkless, toothless and hairless, becoming smaller as they ascend the stem. Stems are multiple from the base, mostly erect or ascending but sometimes sprawling, branching towards the top, leafy, round in cross section, hairless and smooth.
Fruit is a round capsule about 1/3 inch diameter, the surface glossy, yellowish at maturity, the sepals persistent but withering. The capsule splits from the tip into 10 wedge shaped sections, each with 1 or 2 dark brown to black seeds that become slimy when wet.
Though Minnesota sits at the very eastern edge of its range like many western species, the MN DNR does not consider past collections to be of native origin. Regardless, it is encountered occasionally in road ditches and prairie remnants or in restoration plantings. Two other blue flaxes can also be found here in Minnesota. Common flax (Linum usitatissimum) is a Eurasian species that is cultivated for its fiber, edible seeds and oil. Escaped plants can come from any number of sources including mud from commercial grain trucks, and backyard bird feeders. It is an annual that typically is unbranched, sepals have a fringe of hairs around the edge (ciliate), and leaves are 3-nerved. Garden Flax (L. perenne) is also a European species sold in the garden trade and actually is so similar to L. lewisii that some references treat our native as a variety of it. Technically the only difference is that the styles in Garden Flax can be both longer or shorter than the stamens (heterostylic), while Blue Flax has styles all the same length (homostylic). While Garden Flax can escape cultivation, there have been no identified collections in Minnesota.
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Photos courtesy Peter M. Dziuk taken in Kittson County and in North Dakota.
Have you seen this plant in Minnesota, or have any other comments about it?