Cooperia traubii W. Hayward, Herbertia 3: 63, 65 (fig. s.n.), 66 (figs. 1–3). 1936

Leaf blade dull green, to 1 mm wide. Spathe (2–)3–4 cm. Flowers erect; perianth white, sometimes tinged and veined pink, salverform, (11–)12–15.4 cm; perianth tube primarily white, 9–12.6 cm, diam. uniform, 3/4 or more perianth length, at least 15 times filament length, 3–5 times spathe length; tepals often reflexed; stamens fasciculate, appearing equal; filaments subulate, 0.2–0.4 cm, apex blunt; anthers 4–8 mm; style longer than perianth tube; stigma capitate, exserted more than 2 mm beyond anthers; pedicel absent. 2n = 24.

Flowering early summer--mid fall (Jul--Nov). Primarily sandy loam, open fields, coastal plains; 0--100 m; Tex.; ne Mexico.