Oenothera oakesiana |
Oenothera acutissima |
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Oakes' evening-primrose |
flaming Gorge evening primrose |
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Habit | Herbs biennial, densely silky-strigillose, at least proximally, also sparsely villous with long, appressed hairs, sometimes also villous with spreading, pustulate hairs and/or glandular puberulent distally. | 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 | erect to decumbent, green or flushed with red on proximal parts or throughout, unbranched or bushy and branched from base, with side branches arising obliquely or arcuately from rosette, 10–60 cm. |
(when present) ascending, (1–)several–10, densely leafy, 1–2 cm. |
Leaves | in a basal rosette and cauline, basal 8–30 × 0.5–3 cm, cauline 3.5–20 ×0.5–2.7 cm; blade grayish green to dull green, very narrowly oblanceolate to narrowly oblanceolate or narrowly elliptic, margins flat, subentire or remotely dentate, teeth sometimes blunt, sometimes sinuate-dentate proximally; bracts persistent. |
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 | usually recurved with ascending tip distally, rarely suberect, unbranched. |
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Flowers | opening near sunset; buds erect, 3–5 mm diam., with free tips subterminal, spreading to erect, 2.5–4 mm; floral tube 15–40 mm; sepals green to yellow, flushed with red and dark red flecked or red-striped, 9–17 mm; petals yellow to pale yellow, fading yellowish white to pale yellowish orange, very broadly obcordate, 7–20 mm; filaments 6–15 mm, anthers 3–7 mm, pollen ca. 50% fertile; style 20–45 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 | erect or slightly spreading, usually rusty brown when dry, narrowly lanceoloid to lanceoloid, 15–40 × 4–8 mm, free tips of valves 0.5 mm. |
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 | 1.1–1.2 ×0.8–1 mm. |
asymmetrically cuneiform, 2–2.5 mm. |
2n | = 14. |
= 14. |
Oenothera oakesiana |
Oenothera acutissima |
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Phenology | Flowering Jun–Aug. | Flowering May–Jun. |
Habitat | Sandy coastal meadows and dunes, gravelly or rocky sites along rivers, disturbed sites, roadsides. | Restricted to sandy and gravelly, reddish, soil in seasonally wet sites, meadows, depressions, along arroyos, among rocks, in mixed conifer forests, sagebrush scrub. |
Elevation | 0–50(–500) m. (0–200(–1600) ft.) | 1800–2400(–2600) m. (5900–7900(–8500) ft.) |
Distribution |
CT; DC; DE; IL; IN; MA; MD; ME; MI; MN; NH; NJ; NY; OH; PA; RI; VA; VT; WI; MB; NB; NF; NS; ON; PE; QC [Introduced in Europe, Asia]
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CO; UT |
Discussion | Oenothera oakesiana is a PTH species and forms a ring of 14 chromosomes or a ring of 12 and 1 bivalent in meiosis, and is self-compatible and autogamous (W. Dietrich et al. 1997). It has plastome IV and a AC genome composition. (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 | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Oenothera > subsect. Oenothera | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Lavauxia > subsect. Lavauxia |
Sibling taxa | ||
Synonyms | O. biennis var. oakesiana, O. ammophila, O. ammophiloides, O. ammophiloides var. angustifolia, O. ammophiloides var. laurensis, O. atrovirens var. ostreae, O. canovirens var. cymatilis, O. cruciata var. stenopetala, O. cymatilis, O. deflexa var. bracteata, O. disjuncta, O. eriensis, O. eriensis var. niagarensis, O. eriensis var. repandodentata, O. germanica, O. insignis, O. laevigata var. rubripunctata, O. leucophylla, O. litorea, O. magdalena, O. millersii, O. muricata var. parviflora, O. niagarensis, O. nobska, O. oakesiana var. nobska, O. oakesiana var. tidestromii, O. ostreae, O. parviflora var. oakesiana, O. perangusta, O. perangusta var. rubricalyx, O. repandodentata, O. rubescens, O. stenopetala, O. tidestromii, Onagra oakesiana | O. flava var. acutissima |
Name authority | (A. Gray) J. W. Robbins ex S. Watson & J. M. Coulter in A. Gray et al.: Manual ed. 6, 190. (1890) | W. L. Wagner: Syst. Bot. 6: 153, fig. 1. (1981) |
Web links |