89. Oenothera laciniata Hill, Veg. Syst. 12(app.): 64, plate 10. 1767.
[E W]
Oenothera minima Pursh; O. repanda Medikus; O. sinuata Linnaeus; O. sinuata var. minima (Pursh) Nuttall; Onagra sinuata (Linnaeus) Moench; Raimannia laciniata (Hill) Rose ex Britton & A. Brown
Herbs annual, sparsely to moderately strigillose, sometimes also villous, sometimes also becoming glandular puberulent distally. Stems erect to ascending, unbranched to much branched, 5–50 cm. Leaves in a basal rosette and cauline, basal 4–15 × 1–3 cm, cauline 2–10 × 0.5–3.5 cm; blade green, narrowly oblanceolate to narrowly elliptic or narrowly oblong, margins usually dentate or deeply lobed; bracts spreading, flat. Flowers usually 1 opening per day near sunset; buds erect, with free tips erect, 0.3–3 mm; floral tube 12–35 mm; sepals 5–15 mm; petals yellow, fading orange or reddish tinged, broadly obovate or obcordate, 5–22 mm; filaments 3–14 mm, anthers 4–5 mm, pollen ca. 50% fertile; style 20–50 mm, stigma surrounded by anthers at anthesis. Capsules cylindrical, sometimes slightly enlarged toward apex, 20–50 × 2–4 mm. Seeds ellipsoid to subglobose, 0.9–1.8 × 0.4–0.9 mm. 2n = 14.
Flowering (Feb–)Apr–Sep(–Oct). Open, usually sandy sites, disturbed habitats; 0–1000(–1300) m; Ala., Ark., Calif., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Pa., R.I., S.C., S.Dak., Tenn., Tex., Vt., Va., W.Va., Wis., Wyo.; introduced nearly worldwide in temperate and subtropical areas.
Oenothera laciniata is a PTH species and forms a ring of 14 chromosomes in meiosis, and is self-compatible and autogamous (W. Dietrich and W. L. Wagner 1988).
Oenothera laciniata is known in New Mexico from Doña Ana and Roosevelt counties from non-montane habitats and thus do not appear to represent O. pubescens; however, a few collections from Brewster and Jeff Davis counties, Texas, reported by W. Dietrich and W. L. Wagner (1988) as O. laciniata appear to represent collections of O. pubescens. Dietrich and Wagner found that O. laciniata hybridizes not only with O. grandis, but also with O. drummondii subsp. drummondii, O. humifusa, and O. mexicana. It is naturalized nearly worldwide in temperate and subtropical areas.
