Herbs annual, strigillose and also hirsute; from a slender taproot. Stems 5–40 cm. Leaves 1–6 × 0.3–3 cm; petiole 0.1–1.1 cm; blade usually lanceolate to oblanceolate, sometimes elliptic, margins weakly serrate to sinuate-pinnatifid. Flowers 1–3 opening per day near sunset; buds with free tips 0–0.5 mm; floral-tube 5–31 mm; sepals 10–27 mm; petals white, fading pink, 8–25 mm; filaments 6–12 mm, anthers 3–5 mm, pollen 35–65% fertile; style 12–30 mm, stigma surrounded by anthers at anthesis. Capsules broadly clavate or obovoid, 7–31 ×3–5 mm, winged, wings 0.5–1.5 mm, valve surface with prominent midrib, proximal stipe 3–17 mm; sessile. Seeds narrowly obovoid, 0.9–1.2 × 0.4–0.5 mm. 2n = 14.

Phenology: Flowering Feb–May.
Habitat: Alluvial flats, open areas, sandy soil, weedy sites.
Elevation: 10–1300[–2000] m.

Distribution

• Generated Map
• Legacy Map

Tex., Mexico, Central America, n South America, widely in temperate Europe, Asia, Pacific Islands (Hawaii), Australia

Discussion

Oenothera kunthiana is a PTH species and forms a ring of 14 chromosomes in meiosis, and is self-compatible and autogamous, common and widespread from sea level to middle elevations in the mountains from southern Texas south throughout Mexico except for Baja California and the tropical lowlands south­ward to Guatemala, Nicaragua, and Costa Rica; it was once collected in Minas Gerais, Brazil. Oenothera kunthiana was recently found to be naturalized in the Hawaiian Islands.

Oenothera pinnatifida Kunth is a later homonym of O. pinnatifida Nuttall and another later homonym is O. micrantha Walpers, not Hornemann ex Sprengel (1825); they both pertain here.

Selected References

None.

Lower Taxa

None.