Silphium perfoliatum, commonly known as Cup Plant, is a tall, native perennial found in moist prairies, lowland woods, streambanks, and floodplains throughout Illinois. It thrives in full sun to partial shade and moist, well-drained to wet soils, making it ideal for rain gardens, wetland edges, and large native plantings.
This robust plant is named for the unique way its large, opposite leaves join at the stem to form a “cup” that collects rainwater—providing a source of moisture for birds and insects. In mid to late summer, it produces clusters of bright yellow, sunflower-like flowers atop stout square stems that can reach heights of 4 to 10 feet. The plant forms dense clumps and has a bold, architectural presence.
For Illinois native plant enthusiasts, Silphium perfoliatum is a standout choice for prairie restorations, pollinator gardens, and wildlife-friendly landscapes. It attracts bees, butterflies, and hummingbirds while offering water and cover for birds and small creatures. Though large in size and spread, it delivers high ecological value and pairs well with other moisture-loving natives like Joe-Pye Weed, Ironweed, and Swamp Milkweed.
Silphium perfoliatum, commonly known as Cup Plant, is a tall, native perennial found in moist prairies, lowland woods, streambanks, and floodplains throughout Illinois. It thrives in full sun to partial shade and moist, well-drained to wet soils, making it ideal for rain gardens, wetland edges, and large native plantings.
This robust plant is named for the unique way its large, opposite leaves join at the stem to form a “cup” that collects rainwater—providing a source of moisture for birds and insects. In mid to late summer, it produces clusters of bright yellow, sunflower-like flowers atop stout square stems that can reach heights of 4 to 10 feet. The plant forms dense clumps and has a bold, architectural presence.
For Illinois native plant enthusiasts, Silphium perfoliatum is a standout choice for prairie restorations, pollinator gardens, and wildlife-friendly landscapes. It attracts bees, butterflies, and hummingbirds while offering water and cover for birds and small creatures. Though large in size and spread, it delivers high ecological value and pairs well with other moisture-loving natives like Joe-Pye Weed, Ironweed, and Swamp Milkweed.
Bloom: early to mid-summer
Habitats: along ditches near railroads; fence rows; fens and seeps; lake borders; low-lying woodland edges and thickets; moist black soil prairies; moist meadows near rivers
Lifespan: perennial
Moisture: moist
Plant type (height): forb (4 to 10 feet)
Requirements: full sun to partial sun
Soil: loam
