Oenothera texensis |
Oenothera pubescens |
|
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Texas evening primrose |
pubescent evening primrose, silky evening primrose, South American evening-primrose |
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Habit | Herbs perennial, caulescent, strigillose and also sparsely hirsute; from slender taproot. | Herbs annual or biennial, densely to sparsely strigillose, sometimes also villous and glandular puberulent distally; from a taproot. |
Stems | several–many, ascending, unbranched or branched, 25–50 cm. |
unbranched or with branched central stem and ascending to decumbent lateral branches arising from rosette, 5–50(–80) cm. |
Leaves | in a basal rosette and cauline, basal (1–)2.5–6.5 × 0.6–2.3 cm, blade narrowly elliptic to narrowly ovate or ovate, margins weakly serrulate to sinuate-pinnatifid; cauline 1–5.5 × 0.6–2 cm, blade narrowly elliptic to narrowly ovate, margins weakly serrulate. |
in a basal rosette and cauline, basal 5–14 × 0.5–2.5 cm, cauline 2–8 × 0.5–2.5 cm; blade narrowly oblanceolate to narrowly elliptic or narrowly oblong, margins usually dentate to deeply lobed; bracts spreading, flat. |
Inflorescences | erect. |
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Flowers | 1–3 opening per day near sunrise; buds with free tips 0–1 mm; floral tube 15–26 mm; sepals 15–23 mm; petals rose purple, fading darker, 12–25(–30) mm; filaments 9–13 mm, anthers 3.5–6mm, pollen 85–100% fertile; style 26–36 mm, stigma exserted beyond anthers at anthesis. |
usually 1 opening per day near sunset; buds with free tips erect, 0.1–1 mm; floral tube erect, becoming recurved and nodding, then erect again just before anthesis, 15–50 mm; sepals 5–25 mm; petals yellow, fading reddish orange, broadly obovate to obcordate, 5–25(–35) mm; filaments 6–18 mm, anthers (2–)3–9 mm, pollen ca. 50% fertile; style 20–60 mm, stigma surrounded by or slightly exserted beyond anthers at anthesis. |
Capsules | clavate or narrowly obovoid, 9–15 × 3.5–6 mm, apex attenuate to a sterile beak, valve midrib prominent in distal part, proximal stipe 7–12(–28) mm, gradually taperingto base; sessile. |
cylindrical, sometimes slightly enlarged distally, 20–45 ×2–4 mm. |
Seeds | narrowly obovoid, 0.8–1 × 0.2–0.4 mm. |
brown, sometimes dark-flecked, 0.9–1.5 × 0.6–1 mm. |
2n | = 14. |
= 14. |
Oenothera texensis |
Oenothera pubescens |
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Phenology | Flowering May–Sep. | Flowering (Feb–)Apr–Sep(–Oct). |
Habitat | Sandy and gravel bars of streambeds and along streams. | Open sites in montane habitats. |
Elevation | 900–2500 m. (3000–8200 ft.) | (1300–)1500–2500(–3100) m. ((4300–)4900–8200(–10200) ft.) |
Distribution |
TX; Mexico (Coahuila, Tamaulipas) |
AZ; NM; TX; Mexico; West Indies; Central America (Guatemala); South America (Colombia, Ecuador, Peru)
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Discussion | In the flora area, Oenothera texensis is known only from Jeff Davis County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera pubescens 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 pubescens has been collected once in California in 1884 (Newberry Springs, San Bernardino County), where it was temporarily introduced or a natural occurrence that was extirpated. Collections from west Texas (Brewster, Jeff Davis, and Presidio counties) have been made since 1990 and a few others collected earlier were misidentified as O. laciniata. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Anogra amplexicaulis, O. amplexicaulis, O. laciniata subsp. pubescens, Var. o. var. o., O. nyctaginiifolia, O. stuebelii, Raimannia colimae, R. confusa | |
Name authority | P. H. Raven & D. R. Parnell: Madroño 20: 247. (1970) | Willdenow ex Sprengel: Syst. Veg. 2: 229. (1825) |
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