Oenothera linifolia |
Oenothera cinerea |
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threadleaf evening-primrose, threadleaf sundrop |
high-plains beeblossom, woolly beeblossom |
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Habit | Herbs annual, caulescent, strigillose or glabrous, also often glandular puberulent, especially distally; from a sparsely branched taproot. | Herbs suffrutescent, densely soft-villous, hairs mostly appressed, 2–3 mm, becoming less villous distally, also strigillose, rarely glandular puberulent or hispidulous, plant parts grayish green; from deep, twisted, woody rootstock. | ||||
Stems | unbranched or with many ascending branches arising near base, erect, 10–50 cm. |
erect, several-branched near ground, also branched proximal to inflorescences, 60–280 cm. |
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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, 0.5–8 × 0.15–2 cm, sessile, blade narrowly lanceolate or oblanceolate to very narrowly elliptic or linear, margins usually subentire or shallowly sinuate-dentate, sometimes deeply sinuate-dentate, often undulate. |
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Inflorescences | slender. |
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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 1.5–5 mm; sepals 6–14 mm; petals white, fading pink to red, slightly unequal, elliptic, 7–13 mm, clawed; stamens presented in lower 1/2 of flower, filaments 4.5–11 mm, anthers 2–4.5 mm, pollen 90–100% fertile; style 9–19 mm, stigma exserted beyond anthers at anthesis. |
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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. |
lanceoloid to narrowly ovoid, 4-winged, 9–19 × 1–3.5 mm, abruptly constricted to a long, sterile stipe 2–10 mm. |
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Seeds | clustered in each locule, ovoid, surface minutely papillose, 1 × 0.5 mm. |
(1 or)2–4, 2–3(–4) × 0.8–1.3 mm, yellowish to light brown or rarely reddish brown. |
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2n | = 14. |
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Oenothera linifolia |
Oenothera cinerea |
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Phenology | Flowering Apr–Jun(–Aug). | |||||
Habitat | Prairies, open woodlands, open rocky and sandy sites, roadsides. | |||||
Elevation | 0–400 m. (0–1300 ft.) | |||||
Distribution |
AL; AR; FL; GA; IL; KS; KY; LA; MO; MS; NC; OK; SC; TN; TX
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sc United States
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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.) |
Subspecies 2 (2 in the flora). P. H. Raven and D. P. Gregory (1972[1973]) determined Oenothera cinerea to be self-incompatible. The two subspecies recognized here have disjunct distributions but are very similar morphologically. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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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 | ||||||
Subordinate taxa | ||||||
Synonyms | Kneiffia linifolia, O. linifolia var. glandulosa, Peniophyllum linifolium | Gaura cinerea | ||||
Name authority | Nuttall: J. Acad. Nat. Sci. Philadelphia 2: 120. (1821) | (Wooton & Standley) W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 211. (2007) | ||||
Web links |