---
{
  "id": "giant-salvinia",
  "name": "Giant salvinia",
  "scientific": "Salvinia molesta",
  "category": "invasive",
  "status": "Colorado noxious weed · List A — Eradicate",
  "status_sources": [
    "CO-rules-2025"
  ],
  "warning": "Floating mats harm aquatic habitat",
  "warning_tone": "caution",
  "aliases": [],
  "taxonomy_note": "Several floating ferns look similar. Close inspection of leaf hairs is needed; no photo alone establishes identification.",
  "source_ids": [
    "CO-rules-2025",
    "N-salvinia-molesta",
    "S27",
    "Fremont-list-definitions"
  ],
  "description": "Giant salvinia: Floating mats harm aquatic habitat. Identification and evidence for Colorado readers.",
  "claim_evidence": [
    {
      "label": "Recognize",
      "sources": [
        "N-salvinia-molesta"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "giant-salvinia-1"
    },
    {
      "label": "Plants & habitat",
      "sources": [
        "N-salvinia-molesta"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "giant-salvinia-2"
    },
    {
      "label": "People",
      "sources": [
        "N-salvinia-molesta"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "giant-salvinia-3"
    },
    {
      "label": "Dogs & cats",
      "sources": [],
      "scope": "Review limitation",
      "note": "",
      "id": "giant-salvinia-4"
    },
    {
      "label": "Other animals",
      "sources": [
        "N-salvinia-molesta"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "giant-salvinia-5"
    },
    {
      "id": "giant-salvinia-list-meaning",
      "label": "State-list meaning",
      "sources": [
        "Fremont-list-definitions"
      ],
      "scope": "Colorado management-category definition; species classification retains its original status sources",
      "note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
      "reviewed": "2026-09-07"
    }
  ],
  "noxious_class": "A",
  "research": {
    "status": "researching",
    "label": "Still researching this plant",
    "basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
    "open_questions": [
      {
        "area": "Dogs & cats",
        "question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
        "related_claim_ids": [
          "giant-salvinia-4"
        ]
      },
      {
        "area": "Other animals",
        "question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
        "related_claim_ids": [
          "giant-salvinia-5"
        ]
      },
      {
        "area": "Identification",
        "question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
        "related_claim_ids": []
      },
      {
        "area": "Expert review",
        "question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
        "related_claim_ids": []
      }
    ],
    "expert_review": "pending"
  },
  "noxious_class_label": "A — Eradicate",
  "source": "content/plants/giant-salvinia.md"
}
---

# Giant salvinia

*Salvinia molesta*

**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)

Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).

> **Floating mats harm aquatic habitat.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).

**Identification caveat:** Several floating ferns look similar. Close inspection of leaf hairs is needed; no photo alone establishes identification.

## Still researching this plant {#research-status}

This is a sourced working profile. Evidence is incomplete for **Dogs & cats, 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.

![Salvinia molesta: Close view of floating, folded green leaves with textured upper surfaces.](https://denson.github.io/colorado-weed-field-guide/assets/photos/list-a-photos-salvinia-molesta-1.jpg)

**floating foliage** — Close view of floating, folded green leaves with textured upper surfaces.

Photo: Ixitixel; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Salvinia_molesta_(Habitus)_3.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/98/Salvinia_molesta_%28Habitus%29_3.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Salvinia species can be similar. The selected images follow source identifications; the diagnostic joined hair tips are not resolved clearly in every view. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.

![Salvinia molesta: Floating folded leaves with water droplets; the source describes this as a photograph focus-stacked from 20 exposures.](https://denson.github.io/colorado-weed-field-guide/assets/photos/list-a-photos-salvinia-molesta-2.jpg)

**leaf surface** — Floating folded leaves with water droplets; the source describes this as a photograph focus-stacked from 20 exposures.

Photo: Krzysztof Ziarnek, Kenraiz; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Salvinia_molesta_kz16.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/21/Salvinia_molesta_kz16.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Salvinia species can be similar. The selected images follow source identifications; the diagnostic joined hair tips are not resolved clearly in every view. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Source photographer describes the original as focus-stacked from 20 exposures. Gallery display preserves the full image; the catalog preview uses a CSS crop.

![Salvinia molesta: Lake Wilson in Hawaii covered by a dense salvinia mat, with a vehicle and boat on the near shore.](https://denson.github.io/colorado-weed-field-guide/assets/photos/list-a-photos-salvinia-molesta-3.jpg)

**infestation** — Lake Wilson in Hawaii covered by a dense salvinia mat, with a vehicle and boat on the near shore.

Photo: Nani Shimakuku, U.S. Army Corps of Engineers; [Public domain](https://commons.wikimedia.org/wiki/File:Salvinia_molesta_covering_lake.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Salvinia_molesta_covering_lake.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/3d/Salvinia_molesta_covering_lake.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Salvinia species can be similar. The selected images follow source identifications; the diagnostic joined hair tips are not resolved clearly in every view. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.


## Recognize

A floating fern with paired surface fronds and submerged, root-like fronds. Magnification reveals characteristic joined, eggbeater-shaped hairs. [N-salvinia-molesta](https://plants.ces.ncsu.edu/plants/salvinia-molesta/)

## Plants & habitat

Thick mats restrict light and oxygen, clog water intakes and obstruct recreation. Do not introduce it into ponds or discard aquarium material outdoors. [N-salvinia-molesta](https://plants.ces.ncsu.edu/plants/salvinia-molesta/)

## People

Dense surface mats obstruct boating and swimming; this is a water-access hazard rather than a demonstrated ingestion syndrome. [N-salvinia-molesta](https://plants.ces.ncsu.edu/plants/salvinia-molesta/)

## Dogs & cats

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

## Other animals

Habitat effects include reduced oxygen and harm to fish and aquatic plants. Direct livestock toxicity is not established here. [N-salvinia-molesta](https://plants.ces.ncsu.edu/plants/salvinia-molesta/)

## 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](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)

This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)

## References

- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=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-salvinia-molesta** — [salvinia molesta — Plant Toolbox](https://plants.ces.ncsu.edu/plants/salvinia-molesta/), NC State Extension. Accessed 2026-09-07T01:04:51+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.


[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=giant-salvinia) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.

# Appendix for agents

## Open research questions

- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.


## Identity and evidence boundaries

Several floating ferns look similar. Close inspection of leaf hairs is needed; no photo alone establishes identification.

All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.

| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| giant-salvinia-1 | Recognize | Species-specific | N-salvinia-molesta | No quantitative safe exposure established here. |
| giant-salvinia-2 | Plants & habitat | Species-specific | N-salvinia-molesta | No quantitative safe exposure established here. |
| giant-salvinia-3 | People | Species-specific | N-salvinia-molesta | No quantitative safe exposure established here. |
| giant-salvinia-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| giant-salvinia-5 | Other animals | Species-specific | N-salvinia-molesta | No quantitative safe exposure established here. |

## Further work for an agent

- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).

## State-list label provenance

The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.


---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/

Content revised: 2026-09-07T03:50:00Z

Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/index.md

Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/index.md.txt

Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md

Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json