Oenothera platanorum |
Oenothera acutissima |
|
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Fort Huachuca evening primrose |
flaming Gorge evening primrose |
|
Habit | Herbs perennial, caulescent, strigillose, often densely so; from slender taproot. | 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. |
Stems | 1–several, ascending, 5–60 cm. |
(when present) ascending, (1–)several–10, densely leafy, 1–2 cm. |
Leaves | in a basal rosette and cauline, basal 2–7 × 0.3–1.4 cm, blade narrowly elliptic to narrowly ovate, margins weakly serrulate to sinuate-pinnatifid; cauline 1.2–6 × 0.3–1 cm, blade narrowly elliptic to elliptic or ovate, proximal ones sinuate-pinnatifid, margins subentire or weakly serrulate. |
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. |
Inflorescences | erect. |
|
Flowers | 1–3 opening per day near sunrise; buds with free tips 0–0.1 mm; floral tube 9–14 mm; sepals 7.5–13 mm; petals rose purple, fading darker, 8–15 mm; filaments 4–9 mm, anthers 2.5–4 mm, pollen 85–100% fertile; style 12–19 mm, stigma surrounded by anthers at anthesis. |
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. |
Capsules | clavate or narrowly obovoid, 9–14 × 3–4 mm, apex attenuate to a sterile beak, valve midrib prominent in distal part, proximal stipe 4–15 mm, gradually tapering to base; sessile. |
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. |
Seeds | narrowly obovoid, 0.7–0.9 × 0.3–0.5 mm. |
asymmetrically cuneiform, 2–2.5 mm. |
2n | = 14. |
= 14. |
Oenothera platanorum |
Oenothera acutissima |
|
Phenology | Flowering Mar–Aug. | Flowering May–Jun. |
Habitat | Streambeds and near springs. | Restricted to sandy and gravelly, reddish, soil in seasonally wet sites, meadows, depressions, along arroyos, among rocks, in mixed conifer forests, sagebrush scrub. |
Elevation | 700–1900 m. (2300–6200 ft.) | 1800–2400(–2600) m. (5900–7900(–8500) ft.) |
Distribution |
AZ; Mexico (Sonora) |
CO; UT |
Discussion | Oenothera platanorum is known only from the southeastern counties of Cochise, Pinal, and Santa Cruz in Arizona. It was recently collected in Sonora, Mexico. The species is very similar to both O. texensis, from which it differs in its smaller flowers, and the widespread O. rosea, from which it differs in the somewhat larger flowers and in forming seven bivalents in meiosis and fully fertile pollen, whereas O. rosea is a PTH species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | O. flava var. acutissima | |
Name authority | P. H. Raven & D. R. Parnell: Madroño 20: 246. (1970) | W. L. Wagner: Syst. Bot. 6: 153, fig. 1. (1981) |
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