Lewis blue flax

Discuss this plant with the guide — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.

Linum lewisii

Colorado native; low-water garden plant. C-perennials

Ingestion and contact concerns. Native status, garden use and noxious-weed class are separate from toxicity. Exposure help.

Identification caveat: Use Linum lewisii records, not L. perenne or culinary flax L. usitatissimum. The source’s food-use language is not adopted as preparation advice.

Still researching this plant

This is a sourced working profile. Evidence is incomplete for People, Dogs & cats. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. Uncertainty is not a finding that the plant is safe.

Three views of this plant

Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.

**leaf and stem** — Close view of slender narrow leaves along a green flax stem.
Walter Siegmund (talk) · CC BY-SA 3.0
Photo source and identification
Original record · Original image
Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination.
Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.

**flower** — Blue five-petaled flax flowers with pale veins and yellow centers, on a slender flowering stem.
NPS / Jacob W. Frank · Public domain
Photo source and identification
Original record · Original image
Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination.
Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.

**habit** — Airy clump of thin stems carrying numerous blue flowers in dry grassland.
Skoch3 · CC BY-SA 3.0
Photo source and identification
Original record · Original image
Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination.
Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.

Recognize

Delicate five-petaled blue flowers above narrow leaves on slender stems. N-linum-lewisii

Plants & habitat

A short-lived perennial that reseeds freely; reduce seed set if many volunteers are unwanted. It needs sun and drainage. N-linum-lewisii

People

The source flags cyanogenic glycosides and contact dermatitis. This guide does not establish edible preparations or safe doses. N-linum-lewisii

Dogs & cats

Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.

Other animals

Large intake is reported as a concern for cattle and sheep, with potentially severe respiratory effects. Do not assume ornamental flax is suitable feed. N-linum-lewisii

Before taking action

Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. S27

References

C-perennials — Native Herbaceous Perennials for Colorado Landscapes, Colorado State University Extension. Accessed 2026-09-07T00:27:17+00:00. Locator: Description, distribution, hazards, management; see claim locator.
N-linum-lewisii — Linum lewisii — Plant Toolbox, NC State Extension. Accessed 2026-09-07T00:23:59+00:00. Locator: Description, Attributes, Poisonous to Humans, Problems.

Content revised 2026-09-07 02:43:00Z · Source checks dated separately in the references.