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| 1 Plants with long-creeping rhizomes, the culms therefore mostly solitary; terminal spike and uppermost lateral spike usually separated. |
| ..2 Staminate scales with apex rounded to obtuse; widest leaves 1.8-3.0 (-4.4) mm wide; perigynium beak 0.1-0.3 mm long; [widespread] |
..2 Staminate scales with apex acute to awned; widest leaves 2.8-8.3 mm wide; perigynium beak 0.3-0.9 mm long; [of Panhandle FL and AL westward] |
| 1 Plants with short rhizomes, the culms therefore clumped; terminal and uppermost lateral spike usually overlapping. |
| ....3 Leaves green; longest bract blade of uppermost lateral spike 1.6-4.6 (-7.1) cm long; perigynia (1.6-) 1.9-3× as long as thick; [of the Coastal Plain] |
| ....3 Leaves glaucous (rarely green); longest bract blade of uppermost lateral spike 4.1-15.8 cm long; perigynia 1.4-2.2 (-2.4)× as long as thick; [widespread] |