Carex retrorsa

Carex retrorsa, the knotsheath sedge, deflexed bottlebrush sedge, or retrorse sedge, is a widespread species of flowering plant in the family Cyperaceae, native to southern Canada and the northern United States. Preferring wet areas and tolerant of some shade, it is available from speciality nurseries for such uses as ecological restoration projects, erosion control, and rain gardens.