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.
Distribution:
Confirmed observations of Cup plant submitted to the NYS Invasive Species Database. For more information, visit iMapInvasives
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.
Threats & Impacts:
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.
Management Techniques:
Mechanical - small plants may be removed by hand pulling or digging prior to seed set, taking care to remove the entire taproot.
Chemical - apply a selective foliar spray application of glyphosate-based herbicide prior to seed set. Always consult and follow the herbicide product label.
