Sweet-fern

Sweet-fern

Comptonia peregrina

Plant Type
Shrub (Deciduous)
Landscape Layer
Understory
Sun
☀️ Full Sun, ⛅ Part Sun, ☁️ Shade
Moisture
🏜️ Dry, 💧 Regular
Soil
Loam, Sand, Silt, Rocky / Acidic
Bloom
April, May
Sociability
S3 – Small colonies

Pollinator Value

🔑 Keystone
Comptonia supports 66 lepidoptera species as a caterpillar host plant (Eco Region 8 data). As a monotypic genus endemic to North America, it provides unique habitat value. Notable associates include Sphinx gordius, Automeris io, and the specialist Acrobasis comptoniella. Dense rhizomatous colonies provide protective cover for ground-nesting birds including Kirtland's Warbler.

S13 66 lepidoptera; S10 Kirtland's Warbler nesting

🐛 Larval Host
Sphinx gordius, Synchlora aerata, Automeris io, Catocala badia, Acrobasis comptoniella, Protolampra brunneicollis

S13+S15 6 verified Eastern NA

Ecology & Conservation

Proximity Score
0
Native Status
✅ Outaouais ✅ Ottawa ✅ QC ✅ ON
Closest Direction
Local
CEC Eco-Regions
5 – Northern Forests, 5.2 – Mixed Wood Shield, 5.2.3 – Algonquin/Southern Laurentians
Rarity Notes
Secure across its range (G5 globally, N5 in both Canada and US). Not listed under SARA or COSEWIC. Ranked S5 in Ontario and S4 in Quebec. Common in the Ottawa-Hull region historically and currently, with abundant herbarium documentation and community observations.

S22 G5/N5; S26 not SARA listed

Rarity Ranks
QC S4 – Apparently Secure, ON S5 – Secure
Migration
Stable
Ecological Context
A pioneer shrub of dry, sterile, sandy to rocky acidic soils in pine barrens, oak savannas, clearings, and roadsides. Fixes atmospheric nitrogen through actinorrhizal symbiosis with Frankia bacteria, enabling colonization of nutrient-poor substrates. Forms dense rhizomatous colonies on sandy plains and cutover pinelands. In the Outaouais, found on sandy sites such as Constance Bay Sand Hills and Wakefield area.

S6 dry sterile sandy soils; S7 sandy plains; S10 N-fixing pioneer

Permaculture & Companion Planting

Roles
Fire Retardant, Fortress/Barrier, Nitrogen Fixer

S73/S29/S72 Evidence: Fire Retardant: S73 [MEDIUM]: S11 Fire Tolerance = High (not definitional)] | Fortress/Barrier: S61 keyword match: thorns? (supporting signal only)] | Nitrogen Fixer: S73 [HIGH]: S11 classified (S53 no signal, not contradictory)]

Notes
As an actinorhizal nitrogen fixer, sweetfern enriches nutrient-poor sandy soils, benefiting neighboring plants. Forms a natural understory guild with jack pine, black oak, and aspen on acidic sandy sites. Its shallow, spreading root system stabilizes sandy slopes. Suckering habit provides ground cover and erosion control on sites of low fertility. Not listed in Hemenway.

S29 N-fixer, erosion control; S10 sandy soil stabilizer

Medicinal Properties

Always consult a qualified healthcare provider before using any plant for medicinal purposes. The information provided is compiled from secondary sources for educational purposes only.

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Category
Analgesic, Anthelmintic, Astringent, Blood Purifier, Dermatological Aid, Expectorant, Febrifuge, Gynecological Aid, Tonic

S28 Moerman categories; S29 PFAF medicinal uses

Notes
Extensively used by First Nations including Algonquin, Cherokee, Chippewa, Delaware, Malecite, Menominee, and Mi'kmaq. Leaf infusion taken for headaches, fevers, diarrhoea, and catarrh. Leaves applied as poultice for sprains, swellings, toothaches, and poison ivy rash. Cold leaf infusion used externally to counter poison ivy. Root used for headache and inflammation (Mi'kmaq). Compound decoctions used as blood purifier and for bladder inflammation (Delaware). Classified by Health Canada as an approved herbal ingredient (NHP).

S28 42 Moerman uses; S29 PFAF; S36 Health Canada NHP

Edibility & Foraging

Never ingest a plant unless you have 100% certainty of its identity and have consulted multiple reputable sources. The information provided in the Localeaf Plant Database is compiled from secondary sources for educational and historical purposes only.

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✅ Edible   

Foraging Notes
Leaves (fresh or dried) steeped for a fragrant, palatable tea, a use widespread among Algonquin, Chippewa, and other First Nations. Young nutlets edible as a nibble. Leaves also used as a culinary seasoning. PFAF edibility rating 3/5.

S28 Chippewa beverage; S29 tea, seasoning, nibble

Toxicity
⚠️ Moderate Toxicity

No known hazards. USDA Toxicity=None, Bloat=None. Not listed in Cornell poisonous plants database. PFAF reports no known hazards. Contains betulin (leaf, root, stem) per Duke Phytochemical database. Menominee ethnobotanical records mention compound containing leaves used as a poison, but this appears to be a ceremonial/magical context rather than indicating inherent toxicity.

S38 not listed; S11 Toxicity=None; S29 none known; S31 betulin

Seed Source

  • Akene
  • OWSL
Sweet-fern