Plants (15-)31-76 cm (in flower). Leaves: blades on flowering stems, 33-150 × 5-23 mm. Flowers: sepals 31-65 × 3-5.5 mm; petals 27-53 × 5-19 mm; lip (26-)34-55 × 18-24 mm, central keel relatively thin or evidently thin-winged, 3-4 mm wide, deeply and broadly grooved, groove 1.5 mm deep, smooth with 1-3 low, continuous ridges; column 21-25(-29)mm. Capsules (35-)40-65(-80) × 5-10 mm. 2n = 18. Flowering May (Fla.)--Jul (Del.). Coastal Plain savannas, in acidic soil; 0--200 m; Del., Fla., Ga., Md., N.J., N.C., S.C., Va.