Bloomipedia
Lewis flax (Linum lewisii)
Photo: Daughter Dad via iNaturalist · CC BY 4.0 · resized

Flower profile

Lewis flax

Linum lewisii

Lewis flax (Linum lewisii) is a low shrub in the Linaceae family, native in the lower 48 states, blooming mostly May–July across the U.S.

Native in the lower 48

Lewis flax is a wildflower that USDA PLANTS lists as native in the lower 48 states. It's on our flower lists for 7 states, and across the U.S. it's most often seen in bloom in May–July.

23states where USDA records it
7Bloomipedia state lists include it
8,761U.S. sightings*

*iNaturalist research-grade observations, as of October 17, 2026.

On our lists for: Colorado, Idaho, Montana, Nevada, North Dakota, Utah, Wyoming

Quick look

Linum lewisii is a perennial plant in the family Linaceae, native to western North America.

  • It belongs to the Linaceae family. iNaturalist
  • USDA PLANTS describes it as an herb (forb) / a subshrub with a perennial life cycle. USDA PLANTS
  • USDA PLANTS lists it as native in the lower 48 states and records it in 23 states. USDA PLANTS
  • In Colorado, most iNaturalist sightings of it in flower come in June–July. iNaturalist
  • In Utah, most iNaturalist sightings of it in flower come in April–July. iNaturalist
  • USDA PLANTS lists its flower color as blue. USDA PLANTS
  • USDA PLANTS gives its bloom period as indeterminate. USDA PLANTS
  • USDA PLANTS lists a mature height of about 2 ft. USDA PLANTS
  • iNaturalist has 2,176 research-grade sightings of it in Colorado, ranking #72 among the 160 flowers on our Colorado list. iNaturalist
  • iNaturalist has 856 research-grade sightings of it in Utah, ranking #68 among the 153 flowers on our Utah list. iNaturalist
  • iNaturalist has 588 research-grade sightings of it in Wyoming, ranking #40 among the 113 flowers on our Wyoming list. iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (1,104 records)
Bloom time in the 7 states whose Bloomipedia list includes it
StateTypePeak bloomSightings*
ColoradoNativeJune–July2,176
UtahNativeApril–July856
WyomingNativeJune–August588
MontanaNativefew records (19)556
NevadaNativeMay–August521
IdahoNativefew records (14)415
North DakotaNativefew records (9)79

Conservation status

Federal (U.S. ESA)
Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. USFWS ECOS
NatureServe global
G5 Secure worldwide. NatureServe
Colorado
No list Colorado has no state law listing endangered or threatened plants, so we show NatureServe's Colorado ranks instead. NatureServe: S5, secure in Colorado.
Utah
No list Utah has no state law listing endangered or threatened plants, so we show NatureServe's Utah ranks instead. NatureServe: SNR, not yet ranked in Utah.
Wyoming
No list Wyoming has no state law listing endangered or threatened plants, so we show NatureServe's Wyoming ranks instead. NatureServe: S5, secure in Wyoming.
Montana
No list Montana has no state law listing endangered or threatened plants, so we show NatureServe's Montana ranks instead. NatureServe: S5, secure in Montana.
Nevada
Not listed Not on Nevada fully protected plants, critically endangered (NAC 527.010). NatureServe: S4, apparently secure in Nevada. NAC 527.010
Idaho
No list Idaho has no state law listing endangered or threatened plants, so we show NatureServe's Idaho ranks instead. NatureServe: SNR, not yet ranked in Idaho.
North Dakota
No list North Dakota has no state law listing endangered or threatened plants, so we show NatureServe's North Dakota ranks instead. NatureServe: SNR, not yet ranked in North Dakota.
Rare elsewhere
Other states where NatureServe ranks it rare or missing: WV (S2). (S1 critically imperiled, S2 imperiled, SH possibly extirpated, SX presumed extirpated.)

Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.

Can you eat it?

For peopleCaution: partly edible, partly poisonous

NC State Extension lists it as poisonous to humans (severity: medium). Poisonous parts: leaves, sap/juice, seeds, stems. Symptoms they list: “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.” They also note: “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.” NC State Extension

For petsNot well documented

It isn't on the ASPCA plant list, and NC State Extension doesn't flag it for pets.

🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.

Where does it grow?

USDA PLANTS records lewis flax in 23 states.

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Alaska, Arizona, Arkansas, California, Colorado, Idaho, Kansas, Louisiana, Michigan, Minnesota, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oklahoma, Oregon, South Dakota, Texas, Utah, Washington, West Virginia, Wyoming.

Colorado counties with USDA records: Alamosa, Archuleta, Baca, Boulder, Conejos, Costilla, Custer, Delta, Dolores, Douglas, El Paso, Garfield, Gilpin, Grand, Gunnison, Huerfano, Jackson, Jefferson, La Plata, Lake, Larimer, Las Animas, Logan, Mesa, Mineral, Moffat, Montezuma, Montrose, Otero, Park, Pitkin, Pueblo, Rio Blanco, Routt, Saguache, San Juan, San Miguel, Summit, Teller.

Utah counties with USDA records: Beaver, Box Elder, Cache, Carbon, Daggett, Davis, Duchesne, Emery, Garfield, Grand, Iron, Juab, Kane, Millard, Morgan, Piute, Rich, Salt Lake, San Juan, Sanpete, Sevier, Summit, Tooele, Uintah, Utah, Wasatch, Washington, Wayne, Weber.

Wyoming counties with USDA records: Albany, Big Horn, Campbell, Carbon, Converse, Crook, Fremont, Hot Springs, Johnson, Laramie, Lincoln, Natrona, Niobrara, Park, Platte, Sheridan, Sublette, Sweetwater, Teton, Washakie, Weston.

Growing conditions

USDA PLANTS gives Lewis flax a high shade tolerance, medium drought tolerance and low moisture use. It is rated for soil pH 5.6 to 8.4 and winter lows down to -36 °F.

Shade tolerance
High
Drought tolerance
Medium
Moisture use
Low
Soil textures it is adapted to
coarse, medium
Soil pH range
5.6 to 8.4
Minimum temperature tolerated
-36 °F
Frost-free days needed (minimum)
90
Annual precipitation range
10 to 20 inches
Minimum root depth
14 inches
Salinity tolerance
Low
Fertility requirement
Low
Growth rate
Moderate
Lifespan
Moderate
Active growth period
Spring
Fruit or seed
Brown · Spring to Summer
Can be propagated by
seed
Commercial availability
Routinely Available

From the USDA PLANTS characteristics data for LILE3. USDA ratings are general guidance for the species, not a guarantee for your garden.

Names, range and relatives

Native status by region (USDA PLANTS): Alaska: Native; Canada: Native; Lower 48 states: Native.

County records: USDA PLANTS lists it in 323 counties across 21 states; the most are in Colorado (39), California (34), North Dakota (34).

More Colorado flowers

Great mullein (Verbascum thapsus)

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🌼 Blooms in CO: July–October
Blue columbine (Aquilegia coerulea)

Blue columbine

Aquilegia coerulea

★ CO state flowerNative

🌼 Blooms in CO: June–August
Showy milkweed (Asclepias speciosa)

Showy milkweed

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🌼 Blooms in CO: June–July

Sources