Recently segregated from Schoenoplectus, this includes, in Michigan, all the annual, cespitose species. See Hayasaka (2012) and Shiels & Monfils (2012) for further information.
1. Culms sharply triangular.
1. Culms terete or obscurely 3-angled.
2. Achene covered with prominent transverse ridges; perianth bristles none.
2. Achene smooth or obscurely pitted; perianth bristles present or absent.
3. Taller shoots with stems (base of plant to inflorescence) (0.7–) 0.75–0.9 as long as the entire shoot, including the involucral bract; achenes thickly and asymmetrically biconvex (inner face slightly but clearly convex, outer faces forming a clear angle).
3. Taller shoots with stems 0.4–0.75 (–0.8) as long as the entire shoot; achenes flattened-planoconvex (inner face essentially flat, the outer faces gently rounded).
All species found in Schoenoplectiella
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. September 24, 2020. https://michiganflora.net/genus.aspx?id=Schoenoplectiella.