Cup Plant

Cup plant. Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org.

Additional Images

Common Name: Cup plant
Scientific Name: Silphium perfoliatum
Origin: Central United States and Canada

Description

Cup plant is an herbaceous perennial plant in the sunflower family. Mature plants can reach 4-10 feet tall, with a stout central stem that is distinctly four-sided. Leaves are large, up to 8 inches long, and arranged oppositely along the stem. They join together at the base, forming a cup around the central stem that can hold water. Leaves are coarsely toothed and have a very rough, sandpaper-like texture. Plants bloom in early to mid-summer, producing numerous 2-5 inch yellow flowers. Most flowers have 20-35 rays, and a dark yellow center. Small achenes are produced in late-summer, releasing seeds that are spread by wind and water.

Habitat

Cup plant prefers moist soil and full sun, commonly growing along the banks of rivers and streams, in wet meadows, open forested wetlands, and right-of-way drainage ditches.

Threat

Native to parts of the United States, planting of cup plant has often been encouraged in New England. As a result, ornamental plantings have escaped to natural areas where the plants large growth form and high seed production allow it to crowd out desirable native vegetation.

NYS Threat Ranking Assessment Score = High, 77.78

Management

Do not plant cup plant. A relatively new invader to the region, known management strategies for cup plant are limited. Small plants may be removed by hand pulling or digging prior to seed set, taking care to remove the entire tap root. Glyphosate based herbicides may also be an effective tool to control this species.

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