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flaming Gorge evening primrose

Mexican evening primrose, pinkladies, showy 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, glabrate to strigillose, usually also sparsely hirsute; from slender taproot and spreading by rhizomes.
Stems

(when present) ascending, (1–)several–10, densely leafy, 1–2 cm.

many, erect, 4–60 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 2–9 × 0.3–3.2 cm, blade oblanceolate to obovate, margins subentire or sinuate-pinnatifid;

cauline 1–10 × 0.3–3.5 cm, blade narrowly elliptic to ovate, margins subentire or serrulate to sinuate-pinnatifid.

Inflorescences

sharply nodding.

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 in some populations, near sunset in others;

buds with free tips 0–4 mm;

floral tube 12–25 mm;

sepals 15–50 mm;

petals pink to rose, fading darker, or white, fading pink, 15–45 mm;

filaments 10–22 mm, anthers 6–16 mm, pollen 85–100% fertile;

style 20–55 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.

narrowly obovoid to narrowly rhombic-ellipsoid, angled, 10–25 × 3.5–6 mm, apex attenuate to a sterile beak, valve midrib prominent, proximal stipe cylindrical, not tapering to base, (4–)8–15 mm;

sessile.

Seeds

asymmetrically cuneiform, 2–2.5 mm.

narrowly obovoid, 1–1.2 × 0.5–0.6 mm.

2n

= 14.

= 14, 28, 42.

Oenothera acutissima

Oenothera speciosa

Phenology Flowering May–Jun. Flowering (Feb–)Apr–Jul(–Oct).
Habitat Restricted to sandy and gravelly, reddish, soil in seasonally wet sites, meadows, depressions, along arroyos, among rocks, in mixed conifer forests, sagebrush scrub. Grasslands, glades, open woodlands, disturbed places, pastures, rail­roads, roadsides, loamy or sandy soil, sometimes clay.
Elevation 1800–2400(–2600) m. (5900–7900(–8500) ft.) 10–900 m. (0–3000 ft.)
Distribution
from FNA
CO; UT
[BONAP county map]
from FNA
AR; IA; IL; IN; KS; LA; MO; NE; NM; OK; TX; Mexico (Chihuahua, Coahuila, Durango, Nuevo León, San Luis Potosí, Tamaulipas)
[WildflowerSearch map]
[BONAP county map]
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.)

Oenothera speciosa is widely cultivated worldwide for its showy flowers and easy maintenance. It is not known to be definitely naturalized, but tends to persist or become adventive due to its aggressive vegetative reproduction.

(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. Lavauxia > subsect. Lavauxia Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Hartmannia
Sibling taxa
O. albicaulis, O. argillicola, O. arida, O. arizonica, O. biennis, O. boquillensis, O. brachycarpa, O. calcicola, O. californica, O. canescens, O. capillifolia, O. cavernae, O. cespitosa, O. cinerea, O. clelandii, O. coloradensis, O. cordata, O. coronopifolia, O. coryi, O. curtiflora, O. curtissii, O. deltoides, O. demareei, O. dodgeniana, O. drummondii, O. elata, O. engelmannii, O. falfurriae, O. filiformis, O. filipes, O. flava, O. fruticosa, O. gaura, O. gayleana, O. glaucifolia, O. glazioviana, O. grandiflora, O. grandis, O. harringtonii, O. hartwegii, O. havardii, O. heterophylla, O. hispida, O. howardii, O. humifusa, O. jamesii, O. kunthiana, O. laciniata, O. lavandulifolia, O. lindheimeri, O. linifolia, O. longissima, O. macrocarpa, O. mckelveyae, O. mexicana, O. nealleyi, O. neomexicana, O. nutans, O. nuttallii, O. oakesiana, O. organensis, O. pallida, O. parviflora, O. patriciae, O. perennis, O. pilosella, O. platanorum, O. podocarpa, O. primiveris, O. psammophila, O. pubescens, O. rhombipetala, O. riparia, O. rosea, O. serrulata, O. sessilis, O. simulans, O. sinuosa, O. spachiana, O. speciosa, O. stricta, O. suffrutescens, O. suffulta, O. tetraptera, O. texensis, O. toumeyi, O. triangulata, O. triloba, O. tubicula, O. villosa, O. wolfii, O. xylocarpa
O. acutissima, O. albicaulis, O. argillicola, O. arida, O. arizonica, O. biennis, O. boquillensis, O. brachycarpa, O. calcicola, O. californica, O. canescens, O. capillifolia, O. cavernae, O. cespitosa, O. cinerea, O. clelandii, O. coloradensis, O. cordata, O. coronopifolia, O. coryi, O. curtiflora, O. curtissii, O. deltoides, O. demareei, O. dodgeniana, O. drummondii, O. elata, O. engelmannii, O. falfurriae, O. filiformis, O. filipes, O. flava, O. fruticosa, O. gaura, O. gayleana, O. glaucifolia, O. glazioviana, O. grandiflora, O. grandis, O. harringtonii, O. hartwegii, O. havardii, O. heterophylla, O. hispida, O. howardii, O. humifusa, O. jamesii, O. kunthiana, O. laciniata, O. lavandulifolia, O. lindheimeri, O. linifolia, O. longissima, O. macrocarpa, O. mckelveyae, O. mexicana, O. nealleyi, O. neomexicana, O. nutans, O. nuttallii, O. oakesiana, O. organensis, O. pallida, O. parviflora, O. patriciae, O. perennis, O. pilosella, O. platanorum, O. podocarpa, O. primiveris, O. psammophila, O. pubescens, O. rhombipetala, O. riparia, O. rosea, O. serrulata, O. sessilis, O. simulans, O. sinuosa, O. spachiana, O. stricta, O. suffrutescens, O. suffulta, O. tetraptera, O. texensis, O. toumeyi, O. triangulata, O. triloba, O. tubicula, O. villosa, O. wolfii, O. xylocarpa
Synonyms O. flava var. acutissima Hartmannia berlandieri, H. reverchonii, O. berlandieri, O. delessertiana, O. hirsuta, O. obtusifolia, O. shimekii, O. spachii, O. speciosa var. berlandieri, O. speciosa var. childsii, O. tetraptera var. childsii, Xylopleurum berlandieri, X. drummondii, X. hirsutum, X. obtusifolium, X. speciosum
Name authority W. L. Wagner: Syst. Bot. 6: 153, fig. 1. (1981) Nuttall: J. Acad. Nat. Sci. Philadelphia 2: 119. (1821)
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