Oenothera gayleana |
Oenothera pubescens |
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pubescent evening primrose, silky evening primrose, South American evening-primrose |
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Habit | Herbs perennial, sometimes suffrutescent, usually strigillose, sometimes glabrous; from a stout taproot. | Herbs annual or biennial, densely to sparsely strigillose, sometimes also villous and glandular puberulent distally; from a taproot. |
Stems | many, ascending to erect, branched from base, 15–30(–40) cm. |
unbranched or with branched central stem and ascending to decumbent lateral branches arising from rosette, 5–50(–80) cm. |
Leaves | 2.5–3.5 × 0.1–0.2 cm, rarely fascicles of small leaves present in non-flowering axils; petiole 0–0.1 cm; blade linear to narrowly linear-lanceolate, folded lengthwise, base long-attenuate, margins subentire or serrulate, apex acute. |
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. |
Flowers | opening near sunrise; buds with free tips 0–0.5 mm; floral tube 7 mm; sepals 4–6 mm, midribs keeled; petals yellow, fading yellow to orange, 15–20 mm; antisepalous filaments 5 mm, antipetalous filaments 2 mm, anthers 3–4 mm, pollen 90–100% fertile; style 10 mm, stigma discoid to quadrangular, 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 | 18–20 × 2 mm, hard, dehiscent 1/2 their length, often tardily dehiscent throughout their length. |
cylindrical, sometimes slightly enlarged distally, 20–45 ×2–4 mm. |
Seeds | oblanceoloid, 1–1.8 mm, sharply angled, apex truncate. |
brown, sometimes dark-flecked, 0.9–1.5 × 0.6–1 mm. |
2n | = 14. |
= 14. |
Oenothera gayleana |
Oenothera pubescens |
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Phenology | Flowering May–Sep. | Flowering (Feb–)Apr–Sep(–Oct). |
Habitat | Gypsum outcrops. | Open sites in montane habitats. |
Elevation | 500–1400 m. (1600–4600 ft.) | (1300–)1500–2500(–3100) m. ((4300–)4900–8200(–10200) ft.) |
Distribution |
NM; TX |
AZ; NM; TX; Mexico; West Indies; Central America (Guatemala); South America (Colombia, Ecuador, Peru)
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Discussion | Oenothera gayleana is a recently discovered gypsum endemic known only from scattered outcrops from De Baca and Eddy counties in New Mexico, and Culberson County in Texas. When published, the delimitation of O. gayleana included populations in Collinsworth and Dickens counties in the Texas panhandle, and adjacent Harmon County in Oklahoma. Subsequent study (B. Cooper et al., unpubl.) has determined they are actually O. serrulata. (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 | B. L. Turner & M. J. Moore: Phytologia 96: 200, figs. 1, 2. (2014) | Willdenow ex Sprengel: Syst. Veg. 2: 229. (1825) |
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