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| 1 Perigynia red-dotted |
| 1 Perigynia not red-dotted. |
| ..2 Perigynia golden yellow or yellowish-brown at maturity |
| ..2 Perigynia dull yellow-green or pale brown at maturity. |
| ....3 Leaves longer than the flowering stem; perigynia 2.0-3.2 mm long, 1.3-1.8 mm wide, the beak 1/3-1/2 the length of the body |
| ....3 Leaves shorter than the flowering stem; perigynia 3.2-4.0 mm long, 2.0-2.6 mm wide, the beak ca. 1/3 as long as the body. |
| ......4 Awn of pistillate scales 1-3 mm long; adaxial surface of perigynia with 3-5 nerves; [wet pine savannas; se. S, south to c. peninsular FL, west to LA] |
......4 Awn of pistillate scales 0.5-1.5 mm long; adaxial surface of perigynia lacking nerves; [prairies; s. IL, MO, se. KS, and OK south to AR and se. TX, and also introduced eastwards in disturbed sites] |