Oenothera spachiana |
Oenothera harringtonii |
|
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spach's evening primrose |
Colorado Springs evening primrose |
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Habit | Herbs annual, densely strigillose; from a sparsely branched taproot. | Herbs robust spring annual or, rarely, surviving a second year, caulescent, hirtellous, also glandular puberulent; from stout taproot. |
Stems | erect, usually unbranched or with few ascending branches, 10–30(–45) cm. |
ascending to erect, stout, unbranched or with lateral stems from basal rosette, densely leafy, 15–30 cm. |
Leaves | in a basal rosette and cauline, basal 2–5 × 0.5–1.5 cm, petiole 0.5–2 cm, blade oblanceolate to elliptic, margins subentire; cauline 3–6 × 0.2–0.6 cm, petiole 0.2–0.6(–1.5) cm, blade narrowly lanceolate to linear, margins subentire. |
10–14(–14.5) × 1.5–2.3(–3) cm; petiole 4.3–6.6 cm; blade narrowly oblanceolate, margins irregularly and coarsely dentate, apex acute. |
Inflorescences | erect, flowers in leaf axils in distal 1/2 of plant. |
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Flowers | opening near sunrise; buds with free tips to 1 mm, erect to spreading; floral tube 4–10 mm; sepals 4–8 mm; petals pale yellow, fading pale pink, 5–14 mm; filaments 3–7 mm, anthers 2–4 mm, pollen 85–100% fertile; style 3–7 mm, stigma surrounded by anthers. |
usually 5–10 per stem opening per day near sunset, with heavy, sweet scent; buds erect; floral tube 31–60 mm; sepals 17–26 mm; petals white, fading pale pink, 20–26 mm; filaments 11–16 mm, anthers 8–11 mm; style 65–96 mm, stigma exserted beyond anthers at anthesis. |
Capsules | broadly clavate, 4-angled, 5–15 × 3–5 mm, stipe 2–5 mm; sessile. |
straight, lanceoloid, obtusely 4-angled, (21–)25–30(–35) × (5–)6–8 mm, tapering to a sterile beak 6–8 mm, dehiscent 1/2–2/3 their length, valve margins with 5–8 conspicuous, irregular tubercles, sometimes 2 or more coalesced into a sinuate ridge, also with conspicuous medial ridge throughout; pedicel 0.5–1 mm. |
Seeds | 1 × 0.5 mm. |
numerous, usually in 2 distinct rows per locule, sometimes rows partially overlapping, narrowly obovoid, 2.1–2.3 × 1–1.3 mm, embryo slightly less than 1/2 seed volume, surface appearing finely striate but papillose under magnification; seed collar with membrane intact at maturity, membrane rarely splitting and separating from collar, margin entire. |
2n | = 14. |
= 14. |
Oenothera spachiana |
Oenothera harringtonii |
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Phenology | Flowering Mar–May. | Flowering May–Jun. |
Habitat | Prairies, open roadsides, sandy places. | On compacted, silty clay to looser rocky and sandy soil in open grassland. |
Elevation | 10–200 m. (0–700 ft.) | 1400–1900 m. (4600–6200 ft.) |
Distribution |
AL; AR; LA; MS; OK; TX |
CO |
Discussion | G. B. Straley (1977) determined Oenothera spachiana to be self-compatible and autogamous. Collections outside the native range of O. spachiana have been made as a ballast weed in Camden County, New Jersey. Oenothera drummondii (Spach) Walpers (1843), not Hooker (1834) is a later homonym and pertains here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera harringtonii is known only from southeastern Colorado from western El Paso and eastern Fremont counties, southeast through Pueblo to Otero counties, and south to Las Animas County; it may also occur in adjacent Colfax and Union counties in New Mexico but has not been collected there. Oenothera harringtonii is self-incompatible (W. L. Wagner et al. 1985; Wagner 2005). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Blennoderma drummondii, Kneiffia spachiana, O. uncinata | |
Name authority | Torrey & A. Gray: Fl. N. Amer. 1: 498. (1840) | W. L. Wagner, Stockhouse & W. M. Klein: Ann. Missouri Bot. Gard. 70: 195. (1983) |
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