Carex muskingumensis #1 (Muskingum Sedge)

Muskingum Sedge, named after the Muskingum River in Ohio, is also known as Palm Sedge because of its uniquely branching whorl of leaves atop the 2-3′ stems. It is a native wetland sedge that spreads readily to form large colonies in favorable conditions in full sun to full shade. If growing in too much shade, however, they have a tendency to flop or to not get as tall and robust. The foliage remains a bright green color until a frost, which turns it to an attractive shade of yellow. The caterpillars of several species of moths and butterflies feed on the leaves, while many birds and mammals make use of the seeds and the dense cover a mature stand of this sedge often provides through the summer.

Sources:
Native Ferns, Moss, & Grasses by William Cullina
Missouri Botanical Garden
Lady Bird Johnson Wildflower Center
Illinois Wildflowers
USDA Plants Database