Herbs, perennial, cespitose, (10–)15–70(–90) cm, base not bulbous. Stems compact. Leaves in narrow to broad fans, 5–50 cm; sheaths soft, base reddish; blade deep green, linear to linear—sword-shaped, flat, not twisted, under 7 mm wide, papillate or smooth, margins smooth or papillate, somewhat scabrous. Inflorescences: scape sheaths exceeded by leaves; scapes linear to filiform, terete proximally, terete or ancipital-2-edged–winged distally, 0.5–3 mm wide, variably ribbed, distally with 3 or more somewhat scabrous ribs, ribs papillate to scabrous; spikes prevalently ovoid, 5–20 mm, apex usually acute; fertile bracts (4–)5–7(–9) mm, margins entire, apex rounded. Flowers: lateral sepals included, slightly curved, 5–7 mm, keel brown, scarious, lacerate; petals unfolding in morning, blade obtriangular, 4 mm; staminodes bearded. Seeds translucent to mealy, ovoid to ellipsoid, 0.5 mm, finely lined longitudinally with small papillae.
N.S., Ont., Ala., Ark., Conn., D.C., Del., Fla., Ga., Ind., Ky., La., Maine, Mass., Md., Mich., Miss., N.C., N.H., N.J., N.Y., Ohio, Okla., Pa., R.I., S.C., Tenn., Tex., Va., Vt., Wis., Central America.
Varieties 3 (3 in the flora).
|1||Leaves and scapes (except for edges and ribs) smooth; scapes somewhat to much widened distally; 2 ribs comparably wider, making wings, smooth or papillate; seeds translucent||Xyris difformis var. difformis|
|1||Leaves and scapes variously papillate or minutely scabrous; scapes not much widened distally; ribs all equally prominent, somewhat scabrous; seeds translucent or mealy.||> 2|
|2||Seeds translucent; leaves spreading-ascending in broad fans, rarely as long as 10 cm, linear–sword-shaped; spikes rarely longer than 5 mm.||Xyris difformis var. curtissii|
|2||Seeds mealy; leaves ascending in broad to narrow fans, rarely shorter than (10–)15 cm, linear; spikes 6–10(–15) mm||Xyris difformis var. floridana|