Silphium terebinthinaceum, commonly known as Prairie Dock, is a tall, native perennial found in prairies, savannas, and open woodlands throughout Illinois. It thrives in full sun and deep, well-drained soils, particularly in rich loam or clay-loam, and is well-suited to dry to mesic prairie conditions.
This bold plant is best known for its large, rough, heart-shaped basal leaves that can grow over a foot long and resemble elephant ears. In mid to late summer, it sends up towering, leafless flower stalks that can reach 3 to 10 feet in height, topped with clusters of bright yellow, sunflower-like blooms that attract bees, butterflies, and other pollinators.
For Illinois native plant enthusiasts, Silphium terebinthinaceum is a dramatic and ecologically valuable addition to prairie gardens, pollinator plantings, and restoration sites. Its deep taproot helps improve soil structure and drought resilience, while its towering flowers provide vertical interest and seasonal color. It pairs well with other tallgrass prairie species like Compass Plant, Big Bluestem, and Blazing Star.
Silphium terebinthinaceum, commonly known as Prairie Dock, is a tall, native perennial found in prairies, savannas, and open woodlands throughout Illinois. It thrives in full sun and deep, well-drained soils, particularly in rich loam or clay-loam, and is well-suited to dry to mesic prairie conditions.
This bold plant is best known for its large, rough, heart-shaped basal leaves that can grow over a foot long and resemble elephant ears. In mid to late summer, it sends up towering, leafless flower stalks that can reach 3 to 10 feet in height, topped with clusters of bright yellow, sunflower-like blooms that attract bees, butterflies, and other pollinators.
For Illinois native plant enthusiasts, Silphium terebinthinaceum is a dramatic and ecologically valuable addition to prairie gardens, pollinator plantings, and restoration sites. Its deep taproot helps improve soil structure and drought resilience, while its towering flowers provide vertical interest and seasonal color. It pairs well with other tallgrass prairie species like Compass Plant, Big Bluestem, and Blazing Star.
Bloom: late summer to early fall
Habitats: gravel prairies; hill prairies; limestone glades; moist to dry black soil prairies; limestone glades; prairie remnants along roadsides and railroads; savannas; seeps; shrub prairies
Lifespan: perennial
Moisture: moist to slightly dry
Plant type (height): forb (3 to 10 feet)
Requirements: full sun
Soil: deep loamy soil (gravelly or rocky soil is tolerated)
