Eastern White Cedar

Thuja occidentalis

Pollinator Value

🐛 Larval Host: Campaea perlata, Automeris io, Patalene olyzonaria, Digrammia continuata, Feralia jocosa, Eupithecia annulata, Hypagyrtis piniata, Hydriomena renunciata, Xestia elimata, Syngrapha alias
S13+S15 10 verified Eastern NA
❄️ Winter Food Source: Seeds and cones persist through winter, consumed by Pine Grosbeak, Pine Siskin, Common Redpoll, and Ruffed Grouse. Red Squirrels cache cones. Dense evergreen stands provide critical thermal cover for White-Tailed Deer, whose preferred winter browse is the foliage and twigs.
S57 Pine Grosbeak, Swainson's Thrush; S10 Ruffed Grouse, Pine Siskin, Common Redpoll, Red Squirrel, deer browse

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: Globally secure (G5) and secure in both Ontario and Quebec (S5/S5). Not SARA-listed. Locally described as rare in the Ottawa-Hull area by Gillett & White 1978, confined to Gatineau Park on the Quebec side. Becomes increasingly rare at the southern edge of its range in Connecticut (S2, Threatened) and Massachusetts (S1, Endangered).
S22 G5, S5/S5; S26 not SARA-listed; S63 rare in Ottawa-Hull; S61 S2 CT, S1 MA
Rarity Ranks: QC S5 – Secure, ON S5 – Secure
Migration: Stable
Ecological Context: Characteristic tree of calcareous cedar swamps and fens across the boreal-temperate transition. In the Outaouais, found on limestone outcrops, rocky ridges, and riparian corridors within Gatineau Park. Thrives on neutral to alkaline soils over bedrock, often forming dense, nearly impenetrable stands in wet depressions. Long-lived (200-800 years), providing structural permanence in late-successional forests.
S7 cedar swamps, limestone; S10 forested fens, rocky cliffs; S61 fens, cliffs, swamps; S63 parc de la Gatineau

Roles: Fortress/Barrier
S73/S29/S72 Evidence: Fortress/Barrier: S61 keyword match: spines? (supporting signal only)]

Category: Antirheumatic, Antiseptic, Antiviral, Astringent, Diaphoretic, Diuretic, Emmenagogue, Febrifuge, Dermatological Aid, Rubefacient
S29 PFAF medicinal categories; S28 Moerman 46 drug uses across multiple nations
Notes: Extensively used by First Nations across eastern Canada. Algonquin of southwestern Quebec used branch decoctions for rheumatism, steam baths for fevers and colds, and cone infusions for infant colic. Chippewa applied leaf charcoal for headaches and burned twigs as smallpox disinfectant. The essential oil has confirmed antiviral activity and is used to treat warts and polyps. Contains thujone; internal use requires medical supervision.
S28 Algonquin Quebec, Chippewa, Cree uses; S29 antiviral, wart treatment

✅ Edible

Foraging Notes: Leafy branchlets brewed as a tea rich in vitamin C, famously used by Jacques Cartier's crew in 1535 to treat scurvy. Pith of young shoots cooked and added to soups. Inner bark dried and ground into flour in times of scarcity. The tea should be avoided by pregnant women due to emmenagogue properties.
S29 shoots, inner bark, tea; S4 scurvy cure history; S28 Chippewa beverage use