Cup Plant (Silphium perfoliatum)

The Prairie's Water Reservoir

Cup Plant (Silphium perfoliatum) is one of the most architecturally unique prairie plants, with leaves that fuse around the stem to form cups that hold water. This remarkable adaptation makes it a keystone species for prairie biodiversity, essentially creating tiny wetland habitats several feet above the ground.

Living Water Stations

The cup-shaped leaves can hold up to a quarter cup of water after rain or dew, creating drinking stations for birds, beneficial insects, and tree frogs throughout the growing season. These miniature pools also become breeding sites for certain insects and provide bathing opportunities for songbirds. Research has shown that Cup Plant's water reservoirs can support over 100 different invertebrate species, creating a vertical aquatic ecosystem in the middle of the prairie.

Deep Roots & Carbon Storage

Cup Plant develops one of the deepest root systems of any prairie plant—reaching 10-15 feet into the soil. This massive underground structure stores enormous amounts of carbon (some estimates suggest up to 15 tons per acre in mature stands) and creates permanent channels for water infiltration. The roots form extensive partnerships with mycorrhizal fungi, creating underground networks that connect to neighboring plants and facilitate nutrient sharing across the prairie community.

Pollinator Powerhouse

The bright yellow flowers bloom for 6-8 weeks in mid to late summer, providing abundant nectar and pollen when many other prairie plants have finished flowering. The flowers are particularly attractive to native bees, butterflies, and beneficial wasps. In fall and winter, the seed heads feed goldfinches, chickadees, and other songbirds.

Unique Facts

• Can live for over 100 years, with some documented plants over a century old
• The square stems can grow 3-8 feet tall, creating important vertical structure in the prairie
• Resin from the plant was used by Indigenous peoples as chewing gum
• Extremely drought-tolerant once established due to its deep roots
• The perfoliate leaves (fused around the stem) are a rare adaptation in North American plants

Cup Plant is a living piece of prairie infrastructure—storing carbon, holding water, feeding wildlife, and connecting underground fungal networks for decades to come.