Oenothera linifolia |
Oenothera jamesii |
|
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threadleaf evening-primrose, threadleaf sundrop |
trumpet evening primrose |
|
Habit | Herbs annual, caulescent, strigillose or glabrous, also often glandular puberulent, especially distally; from a sparsely branched taproot. | 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 | unbranched or with many ascending branches arising near base, erect, 10–50 cm. |
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 1–2(–4) × 0.2–0.6 cm, petiole 0.2–1(–1.5) cm, blade ovate to obovate or narrowly elliptic; cauline 1–4 × less than 0.1 cm, sessile, blade linear or filiform. |
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 | usually 1–3 opening per day near sunrise; buds without free tips; sepals 1.5–2 mm; petals bright yellow, fading pink, obcordate to obovate, 3–5(–7) mm; filaments 1–2 mm, anthers 0.5–1 mm; style 1–2 mm, stigma surrounded by anthers at anthesis. |
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 | ellipsoid-rhombic to subglobose, 4-angled, 4–6(–10) × 1.5–3 mm, stipe 0–4 mm, valve midrib raised at distal end, indehiscent or tardily dehiscent distally; sessile. |
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 | clustered in each locule, ovoid, surface minutely papillose, 1 × 0.5 mm. |
1–1.2 × 0.7–1.3 mm. |
2n | = 14. |
= 14. |
Oenothera linifolia |
Oenothera jamesii |
|
Phenology | Flowering Apr–Jun(–Aug). | Flowering Jul–Sep(–Oct). |
Habitat | Prairies, open woodlands, open rocky and sandy sites, roadsides. | Sandy stream banks, ditches, moist areas, cultivated areas, disturbed roadsides. |
Elevation | 0–400 m. (0–1300 ft.) | (30–)300–1800 m. ((100–)1000–5900 ft.) |
Distribution |
AL; AR; FL; GA; IL; KS; KY; LA; MO; MS; NC; OK; SC; TN; TX
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KS; OK; TX; Mexico (Coahuila, Nuevo León, Puebla) [Introduced in e Asia (Japan), s Africa, Atlantic Islands (Canary Islands)] |
Discussion | Kneiffia linearifolia Spach (1835) is an illegitimate name based on Oenothera linifolia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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. | FNA vol. 10. |
Parent taxa | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Peniophyllum | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Oenothera > subsect. Oenothera |
Sibling taxa | ||
Synonyms | Kneiffia linifolia, O. linifolia var. glandulosa, Peniophyllum linifolium | Onagra jamesii, O. communis var. jamesii |
Name authority | Nuttall: J. Acad. Nat. Sci. Philadelphia 2: 120. (1821) | Torrey & A. Gray: Fl. N. Amer. 1: 493. (1840) |
Web links |