Snow-on-the-mountain

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

Euphorbia marginata

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

Latex can damage skin and eyes; toxic if eaten. Exposure help.

Identification caveat: The same common name is used for Aegopodium podagraria, an unrelated groundcover. This profile and its sap warnings apply to Euphorbia marginata.

Still researching this plant

This is a sourced working profile. Evidence is incomplete for Other animals. 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** — Tall, branching snow-on-the-mountain plant with green lower leaves and white-edged upper foliage.
Mark G · 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.

**flowers-bracts** — Top view of snow-on-the-mountain flower clusters surrounded by white-edged bracts against a dark background.
Michelle W. （鍾偉瑋） · 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.

**upper-foliage** — Snow-on-the-mountain branch held in a hand, showing white leaf margins and small central flower structures.
Mark G · 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.

Identification

An upright annual whose upper leaves develop striking white margins. Tiny flowers sit within the showy pale bracts. Damaged tissues exude milky latex. N-euphorbia-marginata

People

Sap can cause dermatitis, mouth blistering and serious eye damage. Wear gloves and prevent sap contact, especially with eyes. N-euphorbia-marginata

Dogs & cats

NC State flags this species as hazardous to pets. Prevent chewing and contact with latex; the source provides no safe pet exposure amount. N-euphorbia-marginata

Other animals

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

Plants & habitat

A native plains annual also grown as an ornamental. It tolerates dry, poor soil and can reseed into unwanted patches. N-euphorbia-marginata

Management & timing

Handle with protection and remove unwanted plants before seed maturation. Keep freshly cut material inaccessible to children and animals. N-euphorbia-marginata

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.
N-euphorbia-marginata — Euphorbia marginata, NC State Extension. Accessed 2026-09-07T02:23:13+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
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.