Gaura simulans Small, Bull. New York Bot. Gard. 3: 432. 1905; G. angustifolia Michaux 1803, not Oenothera angustifolia Miller 1768; G. angustifolia var. eatonii (Small) Munz; G. angustifolia var. simulans (Small) Munz; G. angustifolia var. strigosa Munz; G. eatonii Small

Herbs annual, glabrate, strigillose, and/or hirtellous; from taproot. Stems usually unbranched, sometimes several-branched from base, 60–180 cm. Leaves in a basal rosette and cauline, 0.8–13 × 0.1–1.6 cm; blade often red-blotched, narrowly lanceolate to narrowly oblanceolate, margins slightly to conspicuously sinuate-dentate. Flowers 3 or 4-merous, often mixed on a single plant, zygomorphic, opening near sunset; floral tube 3–8 mm; sepals 2.5–8 mm; petals white, fading pink, narrowly elliptic-obovate, 4.5–8 mm; filaments 2.5–6 mm, anthers 0.5–2 mm, pollen 90–100% fertile; style 7.5–19 mm, stigma surrounded by or slightly exserted beyond anthers. Capsules ellipsoid or ovoid, 3-(or 4-)angled, 5–9 × 2–3 mm; sessile. Seeds 2–4, yellowish to light brown, 1.2–2.3 × 0.8–1.1 mm. 2n = 14.

Flowering (Feb–)May–Sep(–Nov). Sandy soil in open woodlands, fields, roadsides, primarily in outer Coastal Plain; 0–10 m; Fla., Ga., N.C., S.C.

Oenothera simulans occurs along the Coastal Plain from Cape Hatteras, North Carolina, southward and throughout Florida. It is self-compatible and autogamous (P. H. Raven and D. P. Gregory 1972[1973]). The species occasionally persists through mild winters in the southern part of its range, appearing biennial.

Gaura fruticosa Jacquin 1786, not G. fruticosa Loefling 1758, is an illegitimate later homonym that pertains here.