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trumpet evening primrose

Habit Herbs biennial or winter-annual, usually predominately and densely strigillose, sometimes also villous with scattered, appressed hairs, rarely with a few pustulate hairs, inflorescence sometimes also glandular puberulent.
Stems

erect, usually green, rarely flushed with red, unbranched or with branches arising obliquely from rosette and secondary branches arising from main stem, 60–180 cm.

Leaves

in a basal rosette and cauline, basal 10–30 × 2.5–5 cm, cauline 4–20 × 1–5 cm;

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

bracts persistent.

Inflorescences

erect, usually unbranched, rarely with few lateral branches.

Flowers

opening near sunset;

buds erect, 7–12 mm diam., with free tips terminal, erect, 0.5–3 mm;

floral tube persistent on ovary after anthesis, (60–)80–120(–160) mm;

sepals yellowish green, red-striped to red throughout, 30–55 mm;

petals yellow, fading orange or pale yellow, very broadly obcordate, 40–50 mm;

filaments 23–30 mm, anthers 12–22 mm, pollen 90–100% fertile;

style 90–170(–200) mm, stigma exserted beyond anthers at anthesis.

Capsules

erect or slightly spreading, dull green or gray-green when dry, narrowly lanceoloid, 20–50 × 6–12 mm, free tips of valves 2.5–5 mm.

Seeds

1–1.2 × 0.7–1.3 mm.

2n

= 14.

Oenothera jamesii

Phenology Flowering Jul–Sep(–Oct).
Habitat Sandy stream banks, ditches, moist areas, cultivated areas, disturbed roadsides.
Elevation (30–)300–1800 m. ((100–)1000–5900 ft.)
Distribution
from FNA
KS; OK; TX; Mexico (Coahuila, Nuevo León, Puebla) [Introduced in e Asia (Japan), s Africa, Atlantic Islands (Canary Islands)]
[BONAP county map]
Discussion

Oenothera jamesii has plastome I and a AA genome composition; it is known in the flora area from southern Kansas (Clark County), central Oklahoma, and Texas.

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

Source FNA vol. 10.
Parent taxa 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. 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
Synonyms Onagra jamesii, O. communis var. jamesii
Name authority Torrey & A. Gray: Fl. N. Amer. 1: 493. (1840)
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