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pink evening primrose, rose evening-primrose

nodding evening-primrose

Habit Herbs perennial, caulescent, strigillose and often also sparsely hirsute; from slender taproot. Herbs biennial, often appearing glabrous to naked eye, usually strigillose and sparsely to moderately villous proximal to inflorescence, hairs translucent and with or without pustules, pustules not red (in fresh material), inflorescence glabrous, glandular puberulent, or strigillose and glandular puberulent.
Stems

1–several, ascending to decumbent, 7–65 cm.

erect, red on proximal parts, green on distal ones, rarely red throughout, unbranched or with branches obliquely arising from rosette and secondary branches arising from main stem, 30–200 cm.

Leaves

in a basal rosette and cauline, basal 1–6 × 0.3–2 cm, blade narrowly elliptic to elliptic or ovate, margins subentire, weakly serrulate, or sinuate-pinnatifid;

cauline 1–6 × 0.3–2 cm, blade narrowly elliptic to narrowly ovate, margins subentire or weakly serrulate, proximal ones sinuate-pinnatifid.

in a basal rosette and cauline, basal 10–32 × 3–7 cm, cauline 6–20 × 2–8 cm;

blade green to pale green, narrowly oblanceolate to narrowly obovate, or narrowly elliptic, sometimes lanceolate distally, margins usually flat, rarely undulate, bluntly dentate, teeth widely spaced, sometimes sinuate-dentate proximally;

bracts caducous.

Inflorescences

erect.

erect, unbranched or with secondary branches just proximal to main one.

Flowers

1–3 opening per day near sunrise;

buds with free tips 0.1–1 mm;

floral tube 4–8 mm;

sepals 6–12 mm;

petals rose purple, fading darker, 4–12 mm;

filaments 4–6 mm, anthers 2–3.5 mm, pollen 35–65% fertile;

style 7–13.5 mm, stigma surrounded by anthers at anthesis.

opening near sunset;

buds erect, 4–6 mm diam., with free tips terminal, erect, 1.5–6 mm;

floral tube 30–43 mm;

sepals yellowish green or flushed with red, 10–23 mm;

petals yellow to pale yellow, fading pale yellowish white, very broadly obcordate, 14–25(–30) mm;

filaments 10–25 mm, anthers 4–10 mm, pollen ca. 50% fertile;

style 35–63 mm, stigma surrounded by anthers at anthesis.

Capsules

narrowly obovoid, 4–12 × 2–4 mm, apex attenuate to a sterile beak, proximal stipe 5–20 mm, gradually tapering to base, valve midrib prominent in distal part;

sessile.

erect or slightly spreading, dull green when dry, narrowly lanceoloid to narrowly ovoid, 12–36 × 3–6 mm, free tips of valves 1–1.5 mm.

Seeds

narrowly obovoid, 0.5–0.9 × 0.3–0.5 mm.

1–1.9 × 0.6–0.9 mm.

2n

= 14.

= 14.

Oenothera rosea

Oenothera nutans

Phenology Flowering Mar–Sep. Flowering Jun–Aug(–Sep).
Habitat tropical areas.. Open, often disturbed sites, stream beds, flood plains, slopes, margins of mixed deciduous forests, roadsides, old fields.
Elevation 10–600 m. (0–2000 ft.) (200–)400–1700 m. ((700–)1300–5600 ft.)
Distribution
from FNA
AZ; CA; TX; Mexico; Central America; West Indies; tropical areas [Introduced in South America (Argentina), Europe, Asia, s Africa, Atlantic Islands (Azores, Canary Islands)]
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CT; DE; FL; GA; IN; KY; MA; MD; ME; MI; MO; NC; NH; NJ; NY; OH; PA; SC; TN; VA; VT; WV; ON
[BONAP county map]
Discussion

Oenothera rosea is a PTH species, forming a ring of 14 chromosomes in meiosis, and is self-compatible and autogamous. In the flora area, it is known from Cochise, Pima, and Santa Cruz counties in Arizona, Alameda, Los Angeles, Riverside, San Bernardino, San Diego, San Francisco, and Santa Barbara counties in California (primarily in urban areas), and from southern Texas. It is clearly of North American origin, since all of its close relatives are confined to North America, and has spread south along the Andes. It occurs at 500–3700 m in South America but generally at lower elevations in most areas.

The name Hartmannia affinis Spach is illegitimate, being based on Oenothera virgata; H. gauroides Spach is also illegitimate, being based on O. rosea; O. purpurea Lamarck is a later homonym; these three names pertain here.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Oenothera nutans 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 III and a BB genome composition. The disjunct occurrences of O. nutans in Arkansas and Missouri probably represent unintentional introductions by humans.

(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. Hartmannia Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Oenothera > subsect. Oenothera
Sibling taxa
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. 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. 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
Synonyms Gaura epilobia, Godetia heuckii, Hartmannia rosea, H. rosea var. parvifolia, H. virgata, O. psycrophila, O. rosea var. parvifolia, O. rubra, O. virgata, Xylopleurum roseum O. austromontana, O. biennis subsp. austromontana, O. biennis var. austromontana, O. biennis var. nutans
Name authority L’Héritier ex Aiton: Hort. Kew. 2: 3. (1789) G. F. Atkinson & Bartlett: Rhodora 15: 83. (1913)
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