Stems 2.5-4.5 dm. Leaf blade 1-2 dm × 0.7-2.5 mm. Racemes compact, 3-6 cm. Tepals 4-7 × 0.5-1.5 mm; stamens 2-3.5 mm; anthers yellow; pedicel 4-5 mm. Capsules 10-14 mm including beaks. Seeds 1-1.5 mm, 7-8 mm including bristle-tails.
Flowering mid--late summer. Boggy pine-barrens, pocosins, and wet savannas; of conservation concern; 0--50 m; Del., Md., N.J., N.C., S.C.
Narthecium americanum is listed as rare or endangered in North Carolina (J. L. Amoroso 1997), South Carolina (D. A. Rayner et al. 1979), and New Jersey (D. B. Snyder and V. E. Vivian 1981), and it has been extirpated from Delaware (A. O. Tucker et al. 1979).