Xyris louisianica E. L. Bridges & Orzell

Herbs, 40--80(--85) cm. Leaves (15--)20--40(--44) cm; blade mostly (2--)2.5--3(--5) mm wide, margins papillate to ciliolate. Inflorescences: scapes terete, ribs 2, strong, distal, with additional narrower, but still strong ribs; all ribs scabrous or scabro-ciliolate; spikes ellipsoid to ovoid or lanceoloid, 1--2(--2.7) cm; fertile bracts nearly orbiculate, 5--6.5(--7) mm, margins entire. Flowers: lateral sepals (4.5--)5--6(--7) mm. Seeds 6--7(--8) mm.

Flowering summer--fall. Moist sands and sandy peats of pine savanna, bogs, clearings, ditchbanks, coastal plain; 0--200 m; Ala., Fla., Ga., La., Miss., Tex.

In Louisiana, Alabama, northwest Florida, and Georgia are what appear to be intergrades with Xyris stricta var. stricta.