Cooperia smallii Alexander, Addisonia 21: 7, plate 676. 1939

Leaf blade dull green, to 5 mm wide. Spathe 2.2–4.6 cm. Flowers erect; perianth lemon yellow, salverform to broadly funnelform, 2.5–9 cm; perianth tube yellowish green, 1.1–4.4 cm, diam. uniform, ca. 1/2 perianth length, ca. 3–5 times filament length, somewhat shorter than spathe; tepals usually reflexed; stamens fasciculate to semifasciculate, appearing equal; filaments subulate, 0.4–0.9 cm, apex acute; anthers 3–7 mm; style longer than perianth tube; stigma capitate, among or exserted more than 2 mm beyond anthers; pedicel (0–)0.1–3.5 cm, shorter than spathe. 2n = 53, 54, 58, 70, 72.

Flowering early fall (Sep--Oct). Low, sandy loam, open fields, swales, ditches; 0--10 m; Tex.

Morphology, cytology, and distribution suggest that Zephyranthes smallii (predominantly 2n = 54) arose from hybridization between Z. pulchella (2n = 48) and Z. chlorosolen (2n = 60 in Cameron County) in Brownsville.