White Elm

Ulmus americana

Pollinator Value

🔑 Keystone: Genus Ulmus supports 183 species of butterflies and moths as a larval host in the Ottawa ecoregion, placing it among the most ecologically significant native tree genera. Key dependent lepidoptera include the Question Mark, Mourning Cloak, and Elm Sphinx. The genus provides essential canopy-level habitat structure and food web support across floodplain and upland forests.
S13 183 lepidoptera; S10 habitat associations
🐛 Larval Host: Nerice bidentata, Polygonia interrogationis, Ceratomia amyntor, Scopula limboundata, Nymphalis antiopa, Lochmaeus manteo, Orgyia definita, Acronicta interrupta, Pyrrharctia isabella, Hyles lineata, Limenitis arthemis, Xanthotype sospeta, Acronicta funeralis, Campaea perlata, Paonias excaecatus
S13+S15 15 verified Eastern NA
❄️ Winter Food Source: Buds and residual samaras provide winter food for House Sparrow and Rock Pigeon. Black-capped Chickadee, Purple Finch, Pine Siskin, and American Goldfinch also consume buds and seeds. The species is used as winter cover and nesting habitat by woodpeckers, nuthatches, and chickadees.
S57 House Sparrow, Rock Pigeon; S10 many bird species consume buds/seeds and use for cover

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 G4 but IUCN Endangered due to ongoing losses from Dutch elm disease. Not listed under SARA. The species remains abundant as seedlings and saplings but rarely achieves mature canopy stature due to the DED fungus transmitted by bark beetles.
S22 G4, IUCN EN; S26 not SARA listed; S41 DED impact
Rarity Ranks: QC S4 – Apparently Secure, ON S5 – Secure
Migration: Stable
Ecological Context: American elm is characteristic of floodplain and bottomland forests throughout eastern North America, commonly occurring along streambanks, river terraces, and swamp margins with Silver Maple, Black Ash, and Green Ash. In the Ottawa-Gatineau region it inhabits moist lowland deciduous forests and is an important early successional species in old fields, though Dutch elm disease has reduced mature canopy trees to a fraction of their former abundance.
S41 floodplain/bottomland forests; S7 swamps, early successional; S10 stream banks

Roles: Fortress/Barrier, Wildlife Habitat
S73/S29/S72 Evidence: Fortress/Barrier: S61 keyword match: thorns? (supporting signal only)] | Wildlife Habitat: S72 Hemenway (tables: 7-2, pp. 116)]
Notes: A dominant canopy species in bottomland and floodplain forest guilds, American elm pairs naturally with moisture-loving hardwoods. It serves as Wildlife Habitat (seeds for birds and mammals, canopy nesting) and its rapidly decomposing leaf litter enriches soil with potassium and calcium, functioning as a soil-improving species.
S41 soil-improving species, litter decomposes rapidly; S72 Wildlife Habitat Table 7-2

Category: Analgesic, Antidiarrheal, Antispasmodic, Astringent, Cold Remedy, Cough Medicine, Dermatological Aid, Gynecological Aid, Haemostatic
S28 27 drug uses across multiple categories; S29 Antispasmodic, Astringent, Birthing aid, Haemostatic, Salve
Notes: Extensively used in Indigenous medicine across eastern North America. The Iroquois, Delaware, Choctaw, and Cheyenne used bark infusions and decoctions for coughs, colds, dysentery, menstrual cramps, hemorrhage, and wound treatment. The Cheyenne used bark infusion during pregnancy for fetal stability. The inner bark served as an emollient on tumors and a wash for sore eyes.
S28 35 Moerman drug uses; S29 multiple traditional applications

✅ Edible

Foraging Notes: The Cheyenne used the red inner bark to prepare a coffee-like beverage. Leaves have been consumed raw or cooked. Edibility is limited to minor ethnobotanical uses with no modern culinary significance.
S28 Cheyenne beverage use; S29 leaves raw/cooked, inner bark coffee