Eastern Hemlock

Tsuga canadensis

Pollinator Value

🔑 Keystone: Tsuga supports 106 species of butterflies and moths as a caterpillar host plant in the eastern NA region. As the sole native species in its genus locally, eastern hemlock is a keystone conifer providing irreplaceable larval habitat for specialist Lepidoptera including Campaea perlata and Feralia comstocki [S13+S14].
S13 106 lepidoptera species
🐛 Larval Host: Campaea perlata, Hyalophora cecropia, Orgyia leucostigma, Metalectra quadrisignata, Xanthorhoe labradorensis, Idia americalis, Marathyssa basalis, Clemensia albata, Anticlea vasiliata, Feralia comstocki
S13+S15 10 verified Eastern NA
❄️ Winter Food Source: Seeds consumed by Red Crossbill and White-winged Crossbill through winter. S10 adds Dark-eyed Junco, Pine Siskin, American Goldfinch, and Black-capped Chickadee as seed consumers. Dense evergreen boughs provide critical winter shelter for roosting birds and deer bedding grounds [S10+S61].
S57+S10 crossbills, juncos, siskins; evergreen shelter

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: Ranked S5 in Ontario and S4 in Quebec. Globally ranked G4 with IUCN status Near Threatened due to the hemlock woolly adelgid (Adelges tsugae), which has decimated populations in the Appalachian portion of its range [S22+S10]. Not listed under SARA.
S22+S26 G4 globally, NT IUCN, not SARA listed
Rarity Ranks: QC S4 – Apparently Secure, ON S5 – Secure
Migration: Stable
Ecological Context: A dominant late-successional conifer of cool, moist ravines and north-facing slopes throughout the mixed forests of the Algonquin/Southern Laurentians ecoregion [S7+S10]. Typically found with beech, sugar maple, and yellow birch on acidic rocky substrates. Produces tannins that dye nearby streams reddish-brown. Increasingly threatened by the introduced hemlock woolly adelgid (Adelges tsugae) [S10+S61].
S7+S10+S61 mixed forest dominant, ravine specialist

Roles: Fire Retardant, Fortress/Barrier
S73/S29/S72 Evidence: Fire Retardant: S73 [MEDIUM]: S11 Fire Tolerance = Medium (not definitional)] | Fortress/Barrier: S61 keyword match: spines? (supporting signal only)]

Category: Astringent, Antiseptic, Diaphoretic, Styptic, Antirheumatic, Diuretic, Dermatological Aid, Antidiarrheal
S28+S29 8 primary categories from Moerman and PFAF
Notes: Extensively used by First Nations peoples including Abnaki, Algonquin (Quebec), Cherokee, Chippewa, and Delaware. Bark is rich in tannin and valued for astringent and antiseptic properties; a decoction treats diarrhoea, colitis, and cystitis. Inner bark infusion used for colds and abdominal pain; pulverized bark applied to stop bleeding [S28+S29]. Tea from leafy twig tips treats dysentery, kidney ailments, and rheumatism. Algonquin of southwestern Quebec used branch decoctions as poultices for arthritis.
S28+S29 extensive First Nations medicinal use

✅ Edible

Foraging Notes: Inner bark can be dried, ground into powder, and used as a thickening in soups or mixed with cereals for bread, but is considered an emergency food only. Young shoot tips yield a herbal tea and are an ingredient of spruce beer. Leaves and twigs yield spruce oil used commercially to flavour chewing gum and soft drinks. Chippewa peoples used leaves to make a beverage.
S29+S28 emergency bark food, tea from shoot tips