Black Oak

Pollinator Value

🔑 Keystone: Quercus is among the most ecologically important genera in eastern North America. In the Ottawa/Gatineau ecoregion, oaks support 401 species of butterflies and moths as larval host plants. Black oak acorns sustain numerous mammals including squirrels, deer, and bear, while the canopy provides nesting habitat for raptors and warblers. The genus ranks at the very top of Tallamy's keystone plant genera for supporting insect biodiversity.
S13+S10
🐛 Larval Host: Acronicta retardata, Dryocampa rubicunda, Furcula borealis, Haploa clymene, Hypercompe scribonia, Limenitis archippus, Ceratomia amyntor, Lochmaeus manteo, Orgyia definita, Acronicta interrupta, Limenitis arthemis, Papilio glaucus, Acronicta funeralis, Callosamia promethea, Campaea perlata
S13+S15 15 verified Eastern NA
❄️ Winter Food Source: Acorns persist into winter and are consumed by Blue Jay, Wild Turkey, Ruffed Grouse, Red-headed Woodpecker, Wood Duck, and Common Grackle among others. Squirrels cache acorns throughout autumn, providing a winter food reserve; White-tailed Deer, Eastern Chipmunk, and other mammals also rely on acorn mast. The large acorn crop every 2-3 years makes black oak a critical mast species for overwintering wildlife.
S57+S10+S41

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 assessed as Least Concern by IUCN. In Ontario ranked S4 (Apparently Secure) with widespread populations across the southern part of the province. Not listed under SARA or COSEWIC. Quebec has no subnational rank, consistent with VASCAN not recognizing native QC populations [S22+S1]. National rank in Canada is N4.
S22+S26+S1
Rarity Ranks: ON S4 – Apparently Secure
Migration: Stable
Ecological Context: Black oak occupies dry, sandy to rocky upland forests across eastern North America, often co-dominant with other oaks and hickories on well-drained ridges and south-facing slopes. In Ontario it reaches its northern range limit, occurring on sandy glacial deposits and exposed Shield outcrops. Despite VASCAN listing it as native only to Ontario, GBIF records 9 preserved specimens in ecoregion 5.2.3 and 8 Gatineau-area observations, suggesting it occurs near the Ottawa River corridor. It favors acidic, nutrient-poor soils where it forms open woodlands with pin oak, scarlet oak, and pignut hickory [S41+S10].
S41+S7+S48+S10

Roles: Fire Retardant, Fortress/Barrier, Insectary Plant, Nutrient Accumulator, Shelterbelter, Wildlife Habitat
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: S72 Hemenway (tables: 6-2, appendix_a, pp. 96, 186)] | Nutrient Accumulator: S72 Hemenway (tables: 6-2, appendix_a, pp. 96, 186)] | Shelterbelter: S72 Hemenway (tables: 6-2, appendix_a, pp. 96, 186); S72 Hemenway (tables: 6-2, appendix_a, pp. 96, 186)] | Wildlife Habitat: S72 Hemenway (tables: 6-2, appendix_a, pp. 96, 186)]
Notes: Black oak functions as a canopy anchor in oak-hickory guild systems, providing mast, insectary habitat, and windbreak services. Its deep taproot mines calcium from subsoil horizons (nutrient accumulator for Ca). Pair with nitrogen-fixers such as New Jersey tea (Ceanothus americanus) on dry acidic sites. The open, irregular crown admits enough light for a productive understory of berry-producing shrubs and shade-tolerant herbs [S41+S72].
S72+S41

Category: Astringent, Antiseptic, Antidiarrheal, Febrifuge, Emetic, Tonic, Dermatological Aid, Respiratory Aid, Throat Aid, Ophthalmic
S28+S29 Cherokee, Delaware, Menominee, Meskwaki traditional uses
Notes: The inner bark was widely used in Indigenous medicine across eastern North America. The Cherokee used bark preparations as an astringent for mouth sores, an antiseptic, an emetic, a febrifuge for intermittent fevers, and for chronic dysentery and indigestion. The Delaware used inner bark infusions as a gargle for colds and hoarseness. The Menominee used a bark decoction as a wash for sore eyes. The bark contains quercitannic acid, which provides its astringent properties; it was also a major commercial source of tannin and yellow dye (quercitron).
S28+S29

✅ Edible

Foraging Notes: Acorns are edible after thorough tannin leaching. The Lakota used acorns to make flour. The Ojibwa considered the acorns equally as good as other oak species after extracting the tannic acid. Acorns can be shelled, diced, and boiled repeatedly until the water runs clear to remove bitterness, then used as flour, thickener, or roasted as a coffee substitute. The traditional method involved burying acorns in boggy ground overwinter to reduce astringency.
S28+S29