The Delaware River watershed runs downhill through forests filled with beech, pine, maple and hemlock. These trees, their leaves and roots clean the water that flows into streams and rivers. Plants that have vital roles include cinnamon fern, which stabilizes the soil; sensitive fern, an indicator of health; and sugar maple, a tree that draws water from deep in the earth and releases it into drier layers to water itself and surrounding plants.
Riparian zones -- riverbanks rich in plants -- serve an important role. These zones prevent erosion, filter runoff, and contain floodwaters. This zone, where land and water meet, is home to some very hard-working plants, including rosebay rhododendron, a blooming shrub that cuts down on erosion and filters water runoff heading for the river; scouring rush, a plant that steadies the sediment and filters water runoff by storing pollutants in its tough stems; and three-lobed cornflower, or "Brown-Eyed Susan," an essential for butterflies, bees and songbirds.
Wet meadow plants working overtime include marsh fern, a primary filter for water entering and leaving the meadow; upright sedge, a plant that forms the foundation of a wet meadow and works as a filter; and spotted joe-pye weed, a tall plant with rose-purple flowers that provides nectar and pollen to the hummingbirds, butterflies, and bees.
Tidal salt marshes are filled with salt marsh cordgrass, an essential plant that grows at the edge of the water and collects sediment to grow the shoreline. Blue-green rush grows in clumps and traps sediments.
Together, these many species of plants work as a team to clean and maintain the watershed and the entire ecosystem that depends on it.
"Nature is a magnificent teacher," explains Victoria Prizzia, founder of Habithque, a Philadelphia-based planning and design studio. "We are pleased to bring some of the beauty and wisdom of the Delaware River Watershed to visitors to this year's Philadelphia Flower Show." Habithque, Inc., developed "Windows on the Watershed," an exhibit funded by the William Penn Foundation at this year's Flower Show, "Wonders of Water," March 3 through 11 at the Pennsylvania Convention Center. For more information visit theflowershow.com.