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long evening primrose, long-stem evening-primrose

pubescent evening primrose, silky evening primrose, South American evening-primrose

Habit Herbs biennial or short-lived perennial, sparsely strigillose, sometimes also villous and with pustulate hairs near inflorescence, sometimes also glandular puberulent. Herbs annual or biennial, densely to sparsely strigillose, sometimes also villous and glandular puberulent distally; from a taproot.
Stems

erect, usually flushed with red proximally or sometimes green, unbranched or with branches obliquely arising from base, secondary branches arising from main stem, 60–300 cm.

unbranched or with branched central stem and ascending to decumbent lateral branches arising from rosette, 5–50(–80) cm.

Leaves

in a basal rosette and cauline, basal 9–40 × 1.4–5 cm, cauline 5–22 × 0.8–2.5 cm;

blade dull green, flat, narrowly oblanceolate, oblanceolate to narrowly elliptic, or narrowly lanceolate, margins bluntly dentate or subentire, teeth widely spaced;

bracts persistent.

in a basal rosette and cauline, basal 5–14 × 0.5–2.5 cm, cauline 2–8 × 0.5–2.5 cm;

blade narrowly oblanceolate to narrowly elliptic or narrowly oblong, margins usually dentate to deeply lobed;

bracts spreading, flat.

Inflorescences

open, erect, unbranched.

Flowers

opening near sunset;

buds erect, 5–9 mm diam., with free tips terminal, erect, 2–6 mm;

floral tube deciduous after anthesis, 60–135 mm;

sepals yellowish green, flushed with some red or red to dark red throughout, 25–55 mm;

petals yellow to pale yellow, fading orange or pale yellow, very broadly obcordate, 28–65 mm;

filaments 20–40 mm, anthers 14–20 mm, pollen 90–100% fertile;

style 90–180 mm, stigma exserted beyond anthers at anthesis.

usually 1 opening per day near sunset;

buds with free tips erect, 0.1–1 mm;

floral tube erect, becoming recurved and nodding, then erect again just before anthesis, 15–50 mm;

sepals 5–25 mm;

petals yellow, fading reddish orange, broadly obovate to obcordate, 5–25(–35) mm;

filaments 6–18 mm, anthers (2–)3–9 mm, pollen ca. 50% fertile;

style 20–60 mm, stigma surrounded by or slightly exserted beyond anthers at anthesis.

Capsules

erect or slightly spreading, dull green or gray-green when dry, narrowly lanceoloid, 25–55 × 4–9 mm, free tips of valves 1–2(–3) mm.

cylindrical, sometimes slightly enlarged distally, 20–45 ×2–4 mm.

Seeds

1–1.9 × 0.6–1.2 mm.

brown, sometimes dark-flecked, 0.9–1.5 × 0.6–1 mm.

2n

= 14.

= 14.

Oenothera longissima

Oenothera pubescens

Phenology Flowering Jul–Sep(–Oct). Flowering (Feb–)Apr–Sep(–Oct).
Habitat Seasonally moist sites, sandy or sandy-loam soil, sites with high alkalinity or associated with limestone, along desert washes, streams, seeps, roadsides. Open sites in mon­tane habitats.
Elevation 800–2800 m. (2600–9200 ft.) (1300–)1500–2500(–3100) m. ((4300–)4900–8200(–10200) ft.)
Distribution
from FNA
AZ; CA; CO; NM; NV; UT
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; NM; TX; Mexico; West Indies; Central America (Guatemala); South America (Colombia, Ecuador, Peru)
[WildflowerSearch map]
[BONAP county map]
Discussion

Oenothera longissima has plastome I and a AA genome composition.

Oenothera longissima is known from northern and western Arizona, Inyo, Los Angeles, and San Bernardino counties in California, Delta and Montezuma counties in Colorado, eastern Nevada, San Juan County in New Mexico, and southern Utah.

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

Oenothera pubescens is a PTH species and forms a ring of 14 chromosomes in meiosis, and is self-compatible and autogamous (W. Dietrich and W. L. Wagner 1988).

Oenothera pubescens has been collected once in California in 1884 (Newberry Springs, San Bernardino County), where it was temporarily introduced or a natural occurrence that was extirpated. Collections from west Texas (Brewster, Jeff Davis, and Presidio counties) have been made since 1990 and a few others collected earlier were misidentified as O. laciniata.

(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. Oenothera > subsect. Nutantigemma
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. 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. 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 O. clutei, O. longissima subsp. clutei, O. longissima var. clutei Anogra amplexicaulis, O. amplexicaulis, O. laciniata subsp. pubescens, Var. o. var. o., O. nyctaginiifolia, O. stuebelii, Raimannia colimae, R. confusa
Name authority Rydberg: Bull. Torrey Bot. Club 40: 65. (1913) Willdenow ex Sprengel: Syst. Veg. 2: 229. (1825)
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