Including Sparganiaceae of Michigan Flora.
1. Pistillate flowers in one to several spherical heads; perianth of greenish sepals; leaves strongly keeled (3-angled in cross-section).
1. Pistillate flowers in an elongate densely flowered spike; perianth of white hairs; leaves flat-elliptic in cross-section.
All species found in Typhaceae
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. March 22, 2019. https://www.michiganflora.net/family.aspx?id=TYPHACEAE.