Cup Plant, Silphium perfoliatum

Cup Plant

Silphium perfoliatum

Benefits:
Sun Shade:
Bloom Time: Summer
Zones: 3, 4, 5
Soil Conditions: Clay, Loam, Sand
Soil Moisture: Moist, Medium, Wet
Color: Yellow
Fragrance: No
Height: 3 - 10 feet
Spacing: 2 feet


Description
Cup Plant (Silphium perfoliatum) is a coarse, sunflower-like, native plant which occurs in low woods and thickets, meadows, prairie stream/pond peripheries and along railroad tracks. It typically grows on tough, erect stems to 4-8 feet tall and is distinguished from the other silphiums by its square/quadrangular stems and pairs of cup-forming leaves. Flower heads (to 3 inches diameter) featuring light yellow rays (20-40) and darker yellow center disks bloom in summer on the upper part of the plant. Rough, triangular to ovate, coarsely-toothed, opposite, connate-perfoliate, medium green leaves. Lower leaves (to 14 inches long) are united at the petioles. Middle and upper leaves lack petioles, and leaf pairs are united at the bases to envelop the stem forming a cup (hence the common name). This species is also commonly called cup rosin weed because its stems (like those of all silphiums) exude a gummy sap when broken or cut.) The root system consists of a central taproot, and abundant shallow rhizomes that help to spread the plant vegetatively, often forming substantial colonies.

Typical habitats include moist black soil prairies, moist meadows near rivers, low-lying woodland edges and thickets, fens and seeps, lake borders, fence rows, and along ditches near railroads.

Easily grown in average, medium to wet soils in full sun. Prefers moist, rich soils, but tolerates some drought once established. Somewhat slow to establish when grown from seed. Self-seeds in optimum growing conditions.

Plant Notes and Herbal Uses
  A large plant that needs lots of space.
  May topple over during a rainstorm with strong winds.
  Leaf cups will collect rain water.
Further Information

Wild Ones of the Fox Valley Area
Prairie Nursery
Wisconsin DNR
Wisconsin Native Plant Nurseries