Houndstongue
Discuss this plant with the guide — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
Cynoglossum officinale
Colorado noxious weed · List B — Stop the spread. J-houndstongue
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. Category source · What the lists mean.
Toxic to livestock. Native status, garden use and noxious-weed class are separate from toxicity. Exposure help.
Still researching this plant
This is a sourced working profile. Evidence is incomplete for People, Dogs & cats. 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.
Bernd Haynold · CC BY 2.5
Photo source and identification
Original record · Original image
Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination.
Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
Robert Flogaus-Faust · CC BY 4.0
Photo source and identification
Original record · Original image
Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination.
Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
Antti Bilund · CC BY-SA 3.0
Photo source and identification
Original record · Original image
Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination.
Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
Recognize
Hairy leaves form a rosette before stems carry small reddish-purple flowers. A biennial or short-lived perennial. J-houndstongue
Plants & habitat
Introduced from Eurasia; spreads by seed in disturbed rangelands and pastures. Prevent seed production and monitor rosettes. J-houndstongue
People
Species-specific human ingestion effects were not established in the reviewed county source. This is an evidence gap, not proof of safety.
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
Contains alkaloids poisonous to livestock. The county explicitly advises against grazing it. J-houndstongue
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
- J-houndstongue — Houndstongue, Jefferson County, Colorado. Accessed 2026-09-07T00:27:22+00:00. Locator: Description, impacts, Colorado list designation, management.