Oenothera linifolia |
Oenothera sinuosa |
|
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threadleaf evening-primrose, threadleaf sundrop |
wavy-leaf gaura, wavyleaf beeblossom |
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Habit | Herbs annual, caulescent, strigillose or glabrous, also often glandular puberulent, especially distally; from a sparsely branched taproot. | Herbs perennial, usually glabrous, sometimes strigillose and villous, hairs erect; from a woody taproot but spreading by rhizomes (forming extensive colonies). |
Stems | unbranched or with many ascending branches arising near base, erect, 10–50 cm. |
erect, branched below and just above ground, branched also proximal to inflorescences, 40–120(–250) 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, (1–)3–11 × (0.1–)0.5–2 cm, blade linear to narrowly oblanceolate, margins usually sparsely sinuate-dentate, rarely subentire, often undulate. |
Inflorescences | stout. |
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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. |
4-merous, zygomorphic, opening near sunset; floral tube 2.5–5 mm; sepals 7–14 mm; petals white, fading pink to red, slightly unequal, elliptic, 7–15 mm; stamens presented in lower 1/2 of flower, filaments 5–11 mm, lanate at very base, anthers 3–5 mm, pollen 90–100% fertile; style 12–19 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. |
narrowly ovoid, narrowly 4-winged or 4-angled, 8–15 × 1.5–3.5 mm, abruptly constricted to a long, sterile stipe 2–8 mm. |
Seeds | clustered in each locule, ovoid, surface minutely papillose, 1 × 0.5 mm. |
(1 or)2–4, light to reddish brown, 2–3 × 1–1.5 mm. |
2n | = 14. |
= 28. |
Oenothera linifolia |
Oenothera sinuosa |
|
Phenology | Flowering Apr–Jun(–Aug). | Flowering Apr–Aug. |
Habitat | Prairies, open woodlands, open rocky and sandy sites, roadsides. | Flats and washes in light sandy loam. |
Elevation | 0–400 m. (0–1300 ft.) | 0–300(–1300) m. (0–1000(–4300) ft.) |
Distribution |
AL; AR; FL; GA; IL; KS; KY; LA; MO; MS; NC; OK; SC; TN; TX
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AL; AR; CA; FL; GA; MO; NY; OK; TX [Introduced in Europe (Italy), s Africa]
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Discussion | Kneiffia linearifolia Spach (1835) is an illegitimate name based on Oenothera linifolia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
P. H. Raven and D. P. Gregory (1972[1973]) determined Oenothera sinuosa to be self-incompatible. Oenothera sinuosa is endemic to Oklahoma and Texas and is escaped or naturalized in Alabama, Arkansas, California (where found to 1300 m), Florida, Georgia, Missouri, and New York. Oenothera sinuosa is potentially a noxious weed due to the aggressive rhizomatous habit, but is somewhat limited by its self-incompatibility. Molecular data (G. D. Hoggard et al. 2004) are consistent with the hypothesis that the allotetraploid (2n = 28) O. sinuosa arose by interspecific hybridization of two species within subsect. Stipogaura as suggested by P. H. Raven and D. P. Gregory (1972[1973]). The molecular data indicate that the pistillate parent came from O. calcicola or a close relative, while the staminate parent originated from the lineage that gave rise to O. cinerea and O. filipes. (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. Gaura > subsect. Stipogaura |
Sibling taxa | ||
Synonyms | Kneiffia linifolia, O. linifolia var. glandulosa, Peniophyllum linifolium | Gaura sinuata |
Name authority | Nuttall: J. Acad. Nat. Sci. Philadelphia 2: 120. (1821) | W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 214. (2007) |
Web links |