Old Switch Panicgrass

Panicum virgatum

Pollinator Value

🐛 Larval Host: Poanes hobomok, Wallengrenia egeremet, Polites themistocles, Ancyloxypha numitor, Enodia anthedon, Anatrytone logan, Hesperia sassacus, Hesperia leonardus, Dargida diffusa, Ostrinia nubilalis, Mythimna unipuncta, Spodoptera frugiperda, Helicoverpa zea
S13+S15 13 verified Eastern NA
❄️ Winter Food Source: Seeds consumed by Snow Bunting (Calcariidae) per avian diet studies. Persistent upright culms and clumps provide structural winter cover for ground-nesting birds and small mammals. Seeds also taken by ground-feeding songbirds and upland gamebirds.
S57 Snow Bunting; S10 cover and seeds; S4 seeds eaten by ground-feeding songbirds

Proximity Score: 1
Native Status: ✅ Outaouais ❌ Ottawa ✅ QC ✅ ON
Closest Direction: S
CEC Eco-Regions: 8 – Eastern Temperate Forests, 8.1 – Mixed Wood Plains, 8.1.1 – Eastern Great Lakes and Hudson Lowlands
Rarity Notes: Imperiled in Quebec (S2), where it is confined to the St. Lawrence River corridor and associated islands. Apparently Secure in Ontario (S4) and globally secure (G5). Not listed under SARA or COSEWIC.
S22 S2 QC, S4 ON, G5; S26 not SARA listed
Rarity Ranks: QC S2 – Imperiled, ON S4 – Apparently Secure
Migration: Stable
Ecological Context: Switchgrass is a dominant warm-season C4 grass of the tallgrass prairie, occurring in dry to moist prairies, open woodlands, sandy savannas, stream banks, and dune systems. In Quebec it is imperiled (S2), confined to St. Lawrence River islands and shorelines. Tolerant of a wide range of soils and disturbance regimes, it colonizes sandy, loamy, and clay substrates from pH 4.5-8.0.
S10 tallgrass prairie dominant; S22 S2 in QC; S7 prairies, dunes, savannas; S54 QC specimens from St. Lawrence islands

Roles: Fire Retardant, Fortress/Barrier, Pollinator Attractor
S73/S29/S72 Evidence: Fire Retardant: S73 [MEDIUM]: S11 Fire Tolerance = High (not definitional)] | Fortress/Barrier: S61 keyword match: prickl (supporting signal only)] | Pollinator Attractor: S73 [HIGH]: S64 Xerces listed (source-classified)]

❌ Not Edible

Foraging Notes: Not edible to humans. No ethnobotanical food uses recorded. Young foliage is palatable to cattle but the plant has shown toxicity in horses, sheep, and goats.
S29 None known; S28 no NAEB uses; S11 Palatable Human=No; S29 toxicity in horses/sheep/goats