Gaura lindheimeri Engelmann & A. Gray, Boston J. Nat. Hist. 5: 217. 1845; G. filiformis Small var. munzii Cory

Herbs clumped perennial, vil­lous, usually more densely so proximally, hairs erect or ± appressed on leaf blades, also glandular puberulent distally, rarely glabrate; from taproot. Stems many from base, ascending or erect, usually branched, 50–150 cm. Leaves in a basal rosette and cauline, 0.5–9 × 0. 1–1.3 cm; blade narrowly elliptic to narrowly oblanceolate, margins coarsely and remotely serrate. Flowers 4-merous, zygomorphic, opening at sunrise; floral tube 4–9 mm; sepals 9–17 mm; petals white, fading light or deep pink, rhombic-obovate to elliptic, 10–15 mm; filaments 7–12 mm, anthers 3.5–4.5 mm, pollen 90–100% fertile; style 16–27 mm, stigma exserted beyond anthers at anthesis. Capsules ellipsoid or ovoid, 4-angled, 6–9 × 2–3.5 mm; sessile. Seeds 1–4, yellowish to light brown, 2–3 × 1–1.5 mm. 2n = 14.

Flowering Apr–Jul(–Oct). Black soil in coastal prairies; 0–100 m; La., Tex.

Oenothera lindheimeri has a fairly narrow distri­bution and occurs only in Acadia, Allen, Beauregard, Calcasieu, Jefferson Davis, Lafayette, St. Mary, Tangipahoa, and Vermillion parishes in Louisiana, and Brazoria, Brazos, Chambers, Fort Bend, Galveston, Hardin, Harris, Jasper, Jefferson, Liberty, Orange, Victoria, and Victoria counties in Texas.

P. H. Raven and D. P. Gregory (1972[1973]) found Oenothera lindheimeri to be self-incompatible. It occasionally forms hybrids with O. filiformis. This species is widely cultivated and has many different cultivars.