Basswood

Tilia americana

Pollinator Value

🔑 Keystone: Tilia supports 143 lepidoptera species in our ecoregion, making it a keystone genus for caterpillar-dependent bird populations. As a dominant canopy tree in the Sugar Maple-Basswood forest type, it anchors food webs in mesic deciduous forests across the Great Lakes and St. Lawrence lowlands.
S13 143 species; S41 Sugar Maple-Basswood type
🐛 Larval Host: Panthea furcilla, Polygonia interrogationis, Ceratomia amyntor, Nymphalis antiopa, Paonias myops, Lochmaeus manteo, Orgyia definita, Acronicta interrupta, Limenitis arthemis, Xanthotype sospeta, Papilio glaucus, Callosamia promethea, Campaea perlata, Paonias excaecatus, Actias luna
S13+S15 15 verified Eastern NA

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 in both Ontario (S5) and Quebec (S4). Not listed under SARA or COSEWIC. Common in the Ottawa-Hull region on both sides of the river. No conservation concerns at provincial or federal level.
S22 S63 S62
Rarity Ranks: QC S4 – Apparently Secure, ON S5 – Secure
Migration: Stable
Ecological Context: A dominant canopy tree in Sugar Maple-Basswood forests (SAF Type 26), reaching maximum development on deep, moist loams of north- and east-facing slopes. Nitrogen-demanding; its calcium-rich leaf litter enriches forest soils. In the Ottawa-Gatineau region, found in rich mesic deciduous forests with sugar maple, beech, and white ash, and occasionally in floodplains. Common on both sides of the Ottawa River.
S41 S12 S63

Roles: Fire Retardant, Fortress/Barrier, Insectary Plant, Pollinator Attractor
S73/S29/S72 Evidence: Fire Retardant: S73 [MEDIUM]: S11 Fire Tolerance = Medium (not definitional)] | Fortress/Barrier: S61 keyword match: thorns? (supporting signal only)] | Insectary Plant: S64 NPPBI 'beneficial insects' flag] | Pollinator Attractor: S73 [HIGH]: S64 Xerces listed (source-classified)]
Notes: PFAF lists basswood as a dynamic accumulator, gathering minerals from deep soil layers and concentrating them in its calcium- and nitrogen-rich leaf litter. Functions as a shelterbelt species with fair wind tolerance. Casts dense shade that limits understory competition; best paired with shade-tolerant ground-layer species. Recommended for woodland garden canopy layer.
S29 dynamic accumulator, shelterbelt; S41 nitrogen-demanding, nutrient-rich litter

Category: Antispasmodic, Demulcent, Diaphoretic, Diuretic, Sedative, Dermatological Aid, Burn Dressing, Eye Medicine, Gastrointestinal Aid, Antihemorrhagic
S28 Moerman 27 Drug uses; S29 PFAF medicinal rating 3/5
Notes: Extensively used by Indigenous peoples across eastern North America. Algonquin of Quebec used leaf infusions as eyewash and leaf poultices medicinally. Cherokee used inner bark decoctions for dysentery, heartburn, and as poultice for boils. Iroquois used compound decoctions of roots and bark for internal hemorrhage, leaf poultices for burns and broken bones, and bark infusions as diuretic. Flower tea is antispasmodic, diaphoretic, and sedative, used for hypertension, feverish colds, and anxiety-related digestive complaints. Health Canada lists Tilia americana as an approved herbal name (NHP).
S28 27 Drug uses across multiple nations; S29 PFAF; S36 NHPID approved

✅ Edible

Foraging Notes: Young twigs and buds eaten raw or cooked as greens by the Chippewa. Leaves are edible raw with a mild, mucilaginous texture suitable for salads. Sap can be drawn and concentrated into syrup. Flowers are used for tea and, combined with ground fruits, yield a chocolate-like paste (though commercially impractical).
S28 Chippewa food use; S29 PFAF edibility rating 3/5