Gaura suffulta Engelmann ex A. Gray, Boston J. Nat. Hist. 6: 190. 1850

Herbs annual, sparsely villous proximally, leaves glabrate to sparsely villous along veins and on margins, usually glabrous distally, except sometimes proximal part of inflorescence, especially bracts, sparsely villous; from stout taproot. Stems usually well-branched, 25–120 cm. Leaves in a basal rosette and cauline, basal 7–11 × 0.1–2.3 cm, blade lyrate; cauline 1–9.5 × 0.1–2.3 cm, blade narrowly lanceolate to linear, margins sinuate-dentate, undulate. Flowers 4-merous, zygomorphic, opening at sunset; floral tube 6.5–14 mm; sepals 11–21 mm; petals white, fading pink to red or sometimes purple, elliptic-obovate, 10–15 mm; filaments 6–9 mm, anthers 2–6 mm, pollen 90–100% fertile; style 16–32 mm, stigma exserted beyond anthers at anthesis. Capsules ovoid, narrowly 4-winged, furrowed between angles, 4.5–8 × 2–5 mm, abruptly tapering to stipe 0–1 mm; sessile. Seeds (1 or)2–4(or 5), yellowish to light brown, 2–3 × 1 mm. 2n = 14.

Flowering Apr–Aug. In open, sandy places; 10–1100 m; Okla., Tex.

Oenothera suffulta is more common in western Texas while uncommon elsewhere throughout Texas, and absent in the Trans-Pecos region. P. H. Raven and D. P. Gregory (1972[1973]) determined O. suffulta to be self-incompatible.