Oenothera laciniata
Oenothera triloba
cut-leaf evening-primrose, southern evening primrose
stemless evening-primrose
erect to ascending, unbranched to much branched, 5–50 cm.
(when present) ascending, 1–several, densely leafy, 0–20 cm.
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.
in a basal rosette, sometimes also cauline, (2.5–)6–25(–32) × (0.6–)1.5–4(–5) cm, thin;
petiole (0.5–)1–8 cm;
blade oblanceolate to elliptic, margins irregularly pinnatifid, sometimes subentire, apex acute to obtuse or rounded.
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.
1–4 opening per day near sunset, without noticeable scent;
buds with subequal free tips 2–7 mm;
floral tube (20–)28–95(–138) mm;
sepals (6–)10–30(–35) mm;
petals pale yellow, fading pale orange, drying lavender, (10–)12–30(–38) mm;
filaments (5–)8–15(–18) mm, anthers (3.5–)4–11 mm;
style (3.4–)4.2–11.5(–16.3) mm, stigma usually surrounded by anthers, sometimes (especially in some Texas populations) exserted beyond anthers.
cylindrical, sometimes slightly enlarged toward apex, 20–50 × 2–4 mm.
woody in age, rhombic-obovoid, winged, wings broadly triangular, 5–10 mm wide, often terminating in a hooked tooth, (10–)15–25(–28) × 4–8 mm (excluding wings), valve surface reticulate, dehiscent 1/8–1/3 their length.
ellipsoid to subglobose, 0.9–1.8 × 0.4–0.9 mm.
asymmetrically cuneiform, (2.1–)2.5–3(–3.3) mm.
= 14.
= 14.
Oenothera laciniata
Oenothera triloba
Oenothera laciniata is a PTH species and forms aring 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.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Oenotheratriloba is primarily a species of the high plains from eastern Socorro County, New Mexico, east through all but eastern Texas, Oklahoma, to southern Kansas, east of Meade and Pawnee counties and south of Douglas and Saline counties. It becomes more sporadic eastward into Missouri south of the Missouri River, northwestern and north-central Arkansas, central and eastern Tennessee, northern Alabama, and Logan and Warren counties, Kentucky; also known from disjunct sites in northern Mexico from Nuevo León, Chihuahua, and Baja California, Mexico; and, introduced in Illinois, Indiana, Ohio, Kentucky (Campbell and Fayette counties), Pennsylvania, Virginia, Maryland, and the District of Columbia. Areas where it was introduced are represented by old collections; no current information indicates their continued presence in any of these areas. It was recently collected in Baca County, Colorado.
Capsules of dead plants sometimes form pineconelike clusters of ten to 100 or more capsules.
The illegitimate names Lavauxia nuttalliana Spach and L. triloba (Nuttall) Spach var. watsonii Britton pertain here.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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