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Blue Flax

Linum lewisii (LY-num loo-WIS-ee-eye)

Family: Linaceae Native Herbaceous (3-15 ft)

Blue Flax is a native, herbaceous perennial with a showy five-petaled, saucer-shaped flower that is pollinated by bees and flies. It is in the Linaceae family. It is native to the Great Plains and western areas of the United States and is commonly found in dry, open areas in the mountains, foothills, prairies, and along roads. Occasionally it is grown in flower gardens further east. The name Linum comes from the Greek name for flax, and lewisii is named for Meriwether Lewis (1774-1809), the famous American explorer. Blue flax will grow up to 24 inches tall with a spread of 1-2 feet, in a mounded shape. It requires full sun and dry, sandy, barren soil. If planted in rich, moist soil the wildflower will droop and sprawl; do not over-water. It will grow in soil that is moderately basic to slightly acidic. This plant self-seeds easily. The root system is a deep taproot. For best results, seed in late fall to early spring; seeding in late summer is not recommended. Each plant only lasts a few years, but they freely self-seed, keeping its presence in the garden. Cut back the top half of the plant after blooming unless many seedlings are desired. Plant blue flax in the garden for movement, color and texture. Use it along sunny garden paths, rocky areas, and in containers. Plants flower profusely, with saucer-shaped flowers that bloom in the morning and then drop off at noon. The blooming season stretches from late spring through summer. The wildflower is easy to grow in areas that are hot and dry. The wildflower attracts pollinators; bees suck nectar and Muscoid flies feed on pollen. The seeds are edible when cooked and have a pleasant, nutty flavor. Native Americans found many uses for blue flax, including using fibrous stems for baskets and crushed stems or leaves in medicinal poultices. insects, Diseases, and other Plant Problems : No serious insect or disease issues; watch for slugs, snails and aphids.

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 68 attributes.

How it fits the guild

Guild layer 4 - Herbaceous (3-15 ft) Optimal soil pH Acid (<6.0); Alkaline (>8.0); Neutral (6.0-8.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Fills a similar niche Campanula divaricata Symphyotrichum oolentangiense Verbena canadensis

Full plant profile

Growing Conditions
Plant type
Herbaceous Perennial; Poisonous
Life cycle
Perennial
USDA zones
4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
Light
Full sun (6 or more hours of direct sunlight a day)
Soil texture
Loam (Silt); Sand; Shallow Rocky
Soil pH
Acid (<6.0); Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage
Available space
12 inches-3 feet
Mature size
Height: 2 ft. 0 in. - 3 ft. 0 in. | Width: 1 ft. 6 in. - 2 ft. 0 in.
Growth rate
Medium
Maintenance
Low
Canopy layer
4 - Herbaceous (3-15 ft)
Form & Appearance
Habit / form
Erect; Mounding; Multi-stemmed
Texture
Medium
Leaf color
Green
Leaf arrangement
Alternate; Whorled
Leaf shape
Lanceolate; Linear
Leaf margin
Entire
Leaf feel
Smooth
Leaf size
1-3 inches long, < 1 inch wide
Hairs present
No
Leaf detail
Alternate gray-green or gray-blue, narrow, oblong leaves appear to be arranged in whorls around lower stems.
Flower color
Blue
Flower value
Showy
Flower form
Raceme
Flower shape
Cup; Saucer
Flower size
1-3 inches
Flower detail
Denim blue flowers open at sunrise and petals fall by noon. The plant usually requires up to 3 years to mature and flower. Each stem ends in a cyme of 10 flowers. When they are budding, the stem droops downward, but when flowers bloom, it is more erect.
Bloom time
Spring; Summer
Fruit color
Gold/Yellow
Fruit type
Capsule
Fruit value
Good Dried
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
The spherical capsules produce up to 10 seeds each. It splits from the tip into 10 sections, each with a dark brown or black seed. Seeds are produced on the lower flowers.
Stem color
Green
Stem detail
Stems are tough and fibrous although they look thin and fragile. The stem is leafy when young; most of the leaves fall off as it matures. There are multiple stems from the base, each one terminating in a cyme of 10 flowers.
Wildlife & Ecology
Native status
Native
Origin
Great Plains, Western U.S. and Canada
Distribution
It is native throughout the Great Plains westward, and North America as far north as Alaska, and as far south as in northern Mexico. It has been introduced in some eastern states, such as West Virginia. It is common along roadsides and meadows.
Wildlife value
Attracts small bees and Muscoid flies. The bees suck the nectar and flies feed on pollen. Deer mice eat the seeds.
Attracts
Bees; Pollinators; Songbirds
Play value
Attracts Pollinators
Food & Medicine
Edible parts
Seeds; Nuts
Fruit type
Capsule

Edibility

Once cooked, the seeds are edible; they must not be eaten raw because they contain cyanide. The seeds have a nutty taste and are nutritious.

Uses (ethnobotany)

Native Americans used Lewis flax in many ways. Fibers from the stems were used in baskets, mats, fishing nets, and snowshoes. Medicinal uses included poultices of crushed leaves and seeds to treat infected wounds, irritated eyes, bruises, etc.

Landscape Use
Landscape location
Container; Meadow; Slope/Bank
Landscape theme
Cottage Garden
Design feature
Border; Small groups
Garden tags
#perennial #pollinator plant #drought tolerant #wildflower #blue flowers #fiber plant
Problems & Resistance
Resistant to
Drought
Propagation
Seed
Fire risk
low flammability
Poison severity
Medium
Poison parts
Leaves; Sap/Juice; Seeds; Stems
Poison symptoms
In animals: severe respiratory difficulty followed shortly by death. Blue flax is unlikely to be a problem unless cattle and sheep eat large quantities of the plant. Seeds and oil are safe for human consumption if they are cooked.
Toxic principle
cyanogenic glycoside
Contact dermatitis
Yes
Toxicity summary
Medium severity poison; parts: Leaves; Sap/Juice; Seeds; Stems; contact dermatitis

Planted at Hunnicutt

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