Flora of the Southeastern United States

1 Lowest spike erect or ascending.

  2 Lower sheaths scabrous, reddish-brown, the sheath fronts (ventral faces) with prominent veins forming a persistent network; lower sheaths usually bladeless, prominently ladder fibrillose

  2 Lower sheaths glabrous, the sheath fronts (ventral faces) not forming a persistent network; lower sheaths usually with leaf blades.

    3 Perigynia evidently nerved on both faces

      4 Pistillate scales with apex acute, acuminate, or mucronate

      4 Pistillate scales (at least the lowermost) with a prominent, scabrous awn

    3 Perigynia not nerved, or very faintly nerved.

        5 Longest bracts overtopping the spikes; perigynia flattened, elliptic to obovate; pistillate scales acute to obtuse, generally shorter than the perigynia

        5 Longest bracts shorter than the spikes; perigynia inflated, obovate; pistillate scales acuminate, longer than the perigynia

1 Lowest spike pendent.

          6 Pistillate scales awnless, the sides black or deep purple-brown; perigynia usually divergent, with apices often slightly reflexed at maturity

          6 Pistillate scales awned, the sides dark reddish-brown, light golden-brown, tan, or clear; perigynia divergent or ascendent, the apices straight or slightly reflexed at maturity.

               8 Achenes lacking a constriction or indentation, the persistent beak usually erect, the body 1.7-1.9 × (1.2-) 1.3-1.6 mm; perigynia (2.4-) 2.8-3.4 × (1.8-) 1.9-2.5 (-2.6) mm, obovate to broad-obovate in outline, rounded at the apex, moderately inflated, with a beak 0.2-0.5 mm long; carpellate scales in the lower ¼ of the spike with awns 2.3-4.2 (-5.1) mm long

               8 Achenes with a constriction or indentation on one margin or rarely across one face and then the achene not plane, the persistent beak often bent and projecting at an angle, the body 1.5-1.8 (-1.9) × 1.2-1.4 mm; perigynia 2.1-3 × 1.3-2 (-2.2) mm, broad-elliptic to obovate in outline, obtuse to rounded at apex, weakly to moderately inflated, with a beak 0.1-0.3 (-0.4) mm long; carpellate scales in the lower ¼ of the spike with awns (3-) 3.9-9.5 mm long

             7 Sheath backs scabrous [prickles (1-) 5-54 per mm2 of sheath surface 5 cm from base]; perigynia flattened, elliptic to ovoid, tapering from near or below the middle to a minute beak; lowest bract of the infructescence 7-35 cm long.

                 9 Perigynia densely granular-papillose throughout, the papillae mostly > 13 μm long; lower pistillate scales usually truncate or retuse, abruptly awned; sheaths finely scabrous; achenes not constricted when at maturity; [more commonly in the piedmont and coastal plain but also scattered inland]

                 9 Perigynia smooth to slightly papillose toward the apex, the papillae mostly < 10 μm long; lower pistillate scales usually acute or acuminate, tapering into the awn; sheaths strongly scabrous; [primarily montane in distribution southward (C. fumosimontana), or montane southward and more commonly in a variety of wetlands northward (C. gynandra)].

                   10 Pistillate and staminate scale bodies dark reddish-brown; apex of pistillate scale bodies retuse with rounded shoulders, the awn extending from the notch; sheath faces with reddish-brown prickles; widest leaves per plant (3-) 4.5-6.5 (-8) mm wide; longest proximal spikes (29-) 42-60 (-76) mm long; longest distal spikes (20-) 29-40 (-48) mm long

                   10 Pistillate and staminate scale bodies clear, tan, or light golden-brown; apex of pistillate scale bodies acuminate to rounded (or rarely obliquely truncate) into the awn base; sheath faces with colorless prickles; widest leaves per plant (5-) 6.5-10.5 (-14) mm wide; longest proximal spikes (35-) 51-93 (-125) mm long; longest distal spikes (20-) 33-58 (-82) mm long