Woodland Sunflower

Helianthus divaricatus

Pollinator Value

🔑 Keystone: Helianthus supports 52 butterfly and moth species as caterpillar host plants in the Ottawa-Gatineau region, making it one of the most ecologically important herbaceous genera. The genus ranks among the top host plant genera for specialist bees, with 36 pollen-specialist bee species documented on Helianthus across eastern North America.
🐛 Larval Host: Hypercompe scribonia, Pyrrharctia isabella, Orgyia leucostigma, Euxoa albipennis, Ogdoconta cinereola, Euxoa ochrogaster, Aglais milberti
🐝 Specialist Bee Host: Andrena accepta, Andrena aliciae, Andrena chromotricha, Andrena helianthi, Andrena peckhami, Melissodes agilis, Pseudopanurgus rugosus, Colletes americanus, Megachile inimica, Megachile pugnata
❄️ Winter Food Source: Sunflower achenes persist on dried stalks into winter and are consumed by a wide range of seed-eating birds. Documented consumers include American Goldfinch, Mourning Dove, Northern Bobwhite, Wild Turkey, Common Grackle, Red-winged Blackbird, White-breasted Nuthatch, and Downy Woodpecker. Small mammals including Gray Squirrel and White-Footed Mouse also feed on the seeds.

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 in Ontario (S5) but vulnerable in Quebec (S3), where populations are concentrated along the Ottawa River valley and the Eardley Escarpment of Gatineau Park. Not listed under SARA or COSEWIC. The species reaches its northeastern range limit in southern Quebec, which likely accounts for its limited provincial distribution.
Rarity Ranks: QC S3 – Vulnerable, ON S5 – Secure
Migration: Stable
Ecological Context: Woodland sunflower occupies dry to mesic open oak-hickory woodlands, forest edges, savannas, and rocky bluffs across the Great Lakes-St. Lawrence lowlands. In the Gatineau region it is closely associated with the Eardley Escarpment, where herbarium specimens document large populations in open oak stands on Precambrian rock outcrops atop Mont King and surrounding cliffs.

Roles: Fortress/Barrier, Insectary Plant, Living Mulch, Pollinator Attractor
Notes: Excellent juglone-tolerant species for planting under or near black walnut. Its rhizomatous spreading habit provides living mulch and ground stabilization in dry woodland openings. Attracts beneficial insects including specialist bees and predatory wasps, making it a strong insectary plant in guild designs.

❌ Not Edible

Foraging Notes: No documented edible uses for this species. The closely related H. tuberosus (Jerusalem artichoke) is widely eaten, but H. divaricatus has no recorded culinary tradition.