Oenothera acutissima |
Oenothera texensis |
|
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flaming Gorge evening primrose |
Texas evening primrose |
|
Habit | Herbs perennial, subacaulescent or very short-caulescent, strigillose mostly along leaf margins and flower parts, also sparsely glandular puberulent, sometimes also sparsely hirsute distally; from a stout taproot, usually with several long, lateral roots often producing adventitious shoots. | Herbs perennial, caulescent, strigillose and also sparsely hirsute; from slender taproot. |
Stems | (when present) ascending, (1–)several–10, densely leafy, 1–2 cm. |
several–many, ascending, unbranched or branched, 25–50 cm. |
Leaves | primarily in a basal rosette, 7–14(–18) × (0.3–)0.5–1(–1.5) cm, moderately thick and stiff; petiole (1.2–)3–5 cm; blade linear to very narrowly elliptic, margins irregularly and coarsely dentate or pinnately lobed, apex long-attenuate. |
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. |
Inflorescences | erect. |
|
Flowers | 1–3 opening per day near sunset; buds with unequal free tips 1–3 mm; floral tube (53–)60–100 mm; sepals 26–50 mm; petals bright yellow, fading deep reddish orange, drying purplish brown, 28–50 mm; filaments 21–35 mm, anthers 9–11 mm; style 75–143 mm, stigma exserted beyond anthers. |
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. |
Capsules | leathery in age, oblong-oblanceoloid, narrowly winged, wings oblong, 1–2(–4) mm wide, broadest near apex, 14–18(–22) × 7–8 mm (excluding wings), apex abruptly constricted, dehiscent 1/4–1/3 their length, valve surface with inconspicuous veins; sessile. |
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. |
Seeds | asymmetrically cuneiform, 2–2.5 mm. |
narrowly obovoid, 0.8–1 × 0.2–0.4 mm. |
2n | = 14. |
= 14. |
Oenothera acutissima |
Oenothera texensis |
|
Phenology | Flowering May–Jun. | Flowering May–Sep. |
Habitat | Restricted to sandy and gravelly, reddish, soil in seasonally wet sites, meadows, depressions, along arroyos, among rocks, in mixed conifer forests, sagebrush scrub. | Sandy and gravel bars of streambeds and along streams. |
Elevation | 1800–2400(–2600) m. (5900–7900(–8500) ft.) | 900–2500 m. (3000–8200 ft.) |
Distribution |
CO; UT |
TX; Mexico (Coahuila, Tamaulipas) |
Discussion | Oenothera acutissima is known only from the vicinity of Manila, eastern Uinta Mountains, Daggett and Duchesne counties, Utah, east to areas in and near the foothills of the Douglas and Blue mountains, in Uinta County, Utah, and Moffat County, Colorado. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
In the flora area, Oenothera texensis is known only from Jeff Davis County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | O. flava var. acutissima | |
Name authority | W. L. Wagner: Syst. Bot. 6: 153, fig. 1. (1981) | P. H. Raven & D. R. Parnell: Madroño 20: 247. (1970) |
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