Cyperus bipartitus, commonly known as Slender Flatsedge, River Cyperus, or Shining Flatsedge, is an annual herb native to a variety of wetland habitats including marshes, wet meadows, stream banks, and lakeshores throughout the Americas. It is adapted to a wide elevation range from 98 to 3740 feet. Slender Flatsedge typically grows up to 10 inches tall with fibrous roots and slender, erect stems. The inflorescence, one to two centimeters long, consists of several flat spikelets, each surrounded by long, leaflike bracts that give the plant a distinctive appearance. The fruit is an achene, which is a small, dry, one-seeded fruit that does not open to release the seed, in this case, a black disc-shaped achene.

This plant is valued for its ability to thrive in wet conditions and is often used in rain gardens, bioswales, and as a soil stabilizer along waterways. It is also appreciated for its delicate structure and the subtle texture it adds to water features and wetland plantings. Slender Flatsedge prefers full sun to part shade and requires consistently moist to wet soil conditions. It is not known for any significant diseases or pests, but it can become invasive if conditions allow for unchecked growth.CC BY-SA 4.0