Curlycup gumweed

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

Grindelia squarrosa

Native Colorado plant · not on state Lists A/B/C. C-floristic-2020 CO-rules-2025

Sticky resin and conditional selenium concern. Exposure help.

Identification caveat: Grindelia squarrosa includes multiple varieties. Photographs and this profile do not constitute a variety-level key or a selenium test.

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

Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.

**habit** — Rounded, densely branching curlycup gumweed plant covered with yellow flower heads.
Jesse Grove · CC0 1.0
Photo source and identification
Original record · Original image
Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted.
Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.

**flower** — Side view of a yellow curlycup gumweed flower head with green, outward-curving bracts below it.
Zach Earl · CC BY 4.0
Photo source and identification
Original record · Original image
Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted.
Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.

**buds-leaves** — Curlycup gumweed buds with spreading green bracts beside toothed leaves on a reddish stem.
Jared Shorma · CC BY 4.0
Photo source and identification
Original record · Original image
Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted.
Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.

Identification

A branching, taprooted biennial or perennial with resinous foliage and flower heads. Growth form varies among the varieties grouped in this species. F-grindelia

People

The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.

Dogs & cats

Sticky secretions are a practical grooming concern, inferred from reports of livestock coats becoming gummed. Pet ingestion toxicity is unresolved. F-grindelia

Evidence scope: Contact precaution inferred from livestock observations.

Other animals

Usually unpalatable to livestock. Resin can gum coats, and the plant can absorb selenium when it is available; this does not mean every specimen contains a toxic concentration. F-grindelia

Plants & habitat

It tolerates dry disturbed ground and may form dense patches on depleted range or roadsides. Native status and weediness depend on context. F-grindelia

Management & timing

Investigate site condition before broad removal. For an unwanted small patch, prevent seed production and monitor replacement vegetation. F-grindelia S27

Evidence scope: Management synthesis.

Before taking action

Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. S27

References

C-floristic-2020 — Colorado Floristic Quality Assessment: 2020 Update, Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
CO-rules-2025 — Colorado Noxious Weed Act rules, 8 CCR 1206-2, Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
F-grindelia — Curlycup gumweed, USDA Forest Service, Fire Effects Information System. Accessed 2026-09-07T02:24:48+00:00. Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management.
S27 — 2103 – Colorado Noxious Weeds, PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.

Content revised 2026-09-07 02:46:00Z · Source checks dated separately in the references.