They are grass-like plants in the familyCyperaceae, commonly known as sedges. Other members of the family Cyperaceae are also called sedges, but those of genus Carex may be called true sedges. Carex has most species in the family.
↑Robert H. Mohlenbrock; Paul Wayne Nelson (1999). "Introduction". Sedges: Carex. Volume 14 of The Illustrated flora of Illinois. Southern Illinois University Press. pp. 3–7. ISBN978-0-8093-2074-5.