- Family (English) Aster
- Family (botanic) Asteraceae
- Tree or plant type Perennial
- Native locale Chicago area, Illinois, North America
- Size range Large plant (more than 24 inches)
- Light exposure Full sun (6 hrs direct light daily), Partial sun / shade (4-6 hrs light daily)
- Hardiness zones Zone 3, Zone 4, Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7, Zone 8, Zone 9
- Soil preference Moist, well-drained soil
- Tolerances Clay soil, Occasional drought, Occasional flooding, Wet sites
- Season of interest midsummer, late summer, early fall
- Flower color and fragrance Yellow
- Shape or form Upright
- Growth rate Fast
- Wildlife Birds, Butterflies, Insect pollinators
Cup plant is a large native species that can grow up to 8 feet tall and produces large, yellow, daisylike flowers from midsummer to early fall. It has unique cupped leaves that surround square stems. Cup plant is a great addition to wildflower gardens, native gardens, cottage gardens, beds, and borders with well-drained soils in full sun. This species is native to the Chicago region according to Swink and Wilhelm’s Plants of the Chicago Region and current research.
Size and method of spreading:
Cup plant can reach heights of 4 to 8 feet and spreads of 1 to 3 feet. The plants spread by self-seeding.
Native geographic location and habitat: (include C-value if appropriate)
The native range of cup plant includes the Eastern and Central United States. C Value: 5.
Attracts birds or pollinators:
Cup plant attracts a variety of bees, butterflies, skippers, wasps, and flies. A variety of birds like the seeds and the water that collects in the cupped leaves.
Cup plant leaves grow in opposite pairs that are fused together to surround the square stems and create cups capable of holding water. Each pair of leaves are at a right angle from the pair above and below (decussate). The leaves can reach up to 6 inches wide and 10 inches long and are broadly lanceolate to ovate. The edges of the leaves are toothed or doubly toothed (dentate or bidentate). The upper and lower surfaces of the leaves are rough to the touch due to short hairs or small epidermal bumps.
Similar to sunflowers, cup plant flowers orient themselves to face the sun. Cup plant produces yellow, daisylike flower heads that are about 3 to 4 inches in diameter. There are between 18 to 40 petal-like, fertile ray flowers that surround numerous disk flowers in the center of the flower heads. At the base of the ray flowers are tubular structures that contain yellow, stringlike structures with divided tips (styles). The inner disk flowers are green until they bloom and turn yellow. After they have flowered, the sterile disk flowers are tubular with a five-lobed tip and contain long, brown structures with long, yellow tips (stamen). Each flower head has a distinct group of 25 to 37 overlapping bracts in two to three layers. They are broadly ovate to elliptic with blunt to sharply pointed tips and hairless except for short, spreading hairs along the margins (ciliate). The flowers occur in branched clusters (panicles) at the terminal ends of the stems.
The fruit of cup plant is small, flat, dry, and does not open to release seeds upon maturity (achenes). The achenes have irregularly rounded, broad wings and are distributed by the wind. The achenes are produced only by the ray flowers.
Cup plant prefers moist soils in full sun to partial shade.
List of pests, diseases, and tolerances:
Cup plant is affected by the head-clipping weevil (Haplorhynchites aeneus), which can clip the flower heads off of the stems. This species is also affected by a fungal blight of the flower heads. It is tolerant of well-drained clay soils, occasional flooding, and short periods of drought.