Oenothera rosea |
Oenothera perennis |
|
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pink evening primrose, rose evening-primrose |
little evening-primrose, perennial evening-primrose, perennial sundrops, small sundrops |
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Habit | Herbs perennial, caulescent, strigillose and often also sparsely hirsute; from slender taproot. | Herbs perennial, sparsely to moderately strigillose, glandular puberulent distally; from fibrous roots. |
Stems | 1–several, ascending to decumbent, 7–65 cm. |
usually erect to slightly decumbent, unbranched to few-branched distally, (3–)15–30(–75) cm. |
Leaves | in a basal rosette and cauline, basal 1–6 × 0.3–2 cm, blade narrowly elliptic to elliptic or ovate, margins subentire, weakly serrulate, or sinuate-pinnatifid; cauline 1–6 × 0.3–2 cm, blade narrowly elliptic to narrowly ovate, margins subentire or weakly serrulate, proximal ones sinuate-pinnatifid. |
in a basal rosette and cauline, basal 2–4 × 0.2–1.2 cm, petiole (0.2–)0.5–1.2(–2.5) cm, blade oblanceolate to obovate; cauline 3–7 × 0.2–1.2 cm, petiole 0.1–1 cm, blade oblanceolate to obovate, margins entire or weakly and remotely denticulate. |
Inflorescences | erect. |
nodding, flowers in axils of distalmost few nodes. |
Flowers | 1–3 opening per day near sunrise; buds with free tips 0.1–1 mm; floral tube 4–8 mm; sepals 6–12 mm; petals rose purple, fading darker, 4–12 mm; filaments 4–6 mm, anthers 2–3.5 mm, pollen 35–65% fertile; style 7–13.5 mm, stigma surrounded by anthers at anthesis. |
opening near sunrise, nearly unscented; buds with free tips to 1 mm, connivent; floral tube 3–10 mm; sepals 2–4 mm; petals bright yellow, fading pale yellow, or orangish yellow to pale pink, 5–10 mm; filaments 3–4 mm, anthers 1–2 mm, pollen 40–70% fertile; style 3–4 mm, stigma surrounded by anthers at anthesis. |
Capsules | narrowly obovoid, 4–12 × 2–4 mm, apex attenuate to a sterile beak, proximal stipe 5–20 mm, gradually tapering to base, valve midrib prominent in distal part; sessile. |
clavate, 4-angled or narrowly 4-winged, 5–10 × 2–3 mm, stipe 1–2 mm; sessile. |
Seeds | narrowly obovoid, 0.5–0.9 × 0.3–0.5 mm. |
0.7–0.8 × 0.2–0.3 mm. |
2n | = 14. |
= 14. |
Oenothera rosea |
Oenothera perennis |
|
Phenology | Flowering Mar–Sep. | Flowering May–Jul(–Aug). |
Habitat | tropical areas.. | Fields, open woods, boggy areas. |
Elevation | 10–600 m. (0–2000 ft.) | (0–)150–900(–1400) m. ((0–)500–3000(–4600) ft.) |
Distribution |
AZ; CA; TX; Mexico; Central America; West Indies; tropical areas [Introduced in South America (Argentina), Europe, Asia, s Africa, Atlantic Islands (Azores, Canary Islands)]
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CT; DC; DE; IA; IL; IN; KY; MA; MD; ME; MI; MN; MO; NC; NE; NH; NY; OH; PA; RI; SC; TN; VA; VT; WI; WV; BC; MB; NB; NF; NS; ON; PE; QC; SPM
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Discussion | Oenothera rosea is a PTH species, forming a ring of 14 chromosomes in meiosis, and is self-compatible and autogamous. In the flora area, it is known from Cochise, Pima, and Santa Cruz counties in Arizona, Alameda, Los Angeles, Riverside, San Bernardino, San Diego, San Francisco, and Santa Barbara counties in California (primarily in urban areas), and from southern Texas. It is clearly of North American origin, since all of its close relatives are confined to North America, and has spread south along the Andes. It occurs at 500–3700 m in South America but generally at lower elevations in most areas. The name Hartmannia affinis Spach is illegitimate, being based on Oenothera virgata; H. gauroides Spach is also illegitimate, being based on O. rosea; O. purpurea Lamarck is a later homonym; these three names pertain here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera perennis, a PTH species that forms a ring of 14 chromosomes in meiosis, is self-compatible and autogamous (G. B. Straley 1977). It is disjunct in Nebraska from the rest of its range in eastern North America, occurring in Garfield, Holt, and Rock counties (R. Kaul, pers. comm.). It is introduced in British Columbia. Oenotherapumila Linnaeus is an illegitimate substitution based on O. perennis Linnaeus, while Kneiffia michauxii Spach is an illegitimate substitution based O. pumila, as is K. pumila Spach, and the three pertain here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Gaura epilobia, Godetia heuckii, Hartmannia rosea, H. rosea var. parvifolia, H. virgata, O. psycrophila, O. rosea var. parvifolia, O. rubra, O. virgata, Xylopleurum roseum | Kneiffia chrysantha, K. depauperata, K. perennis, O. chrysantha, O. perennis var. rectipilis, O. pumila var. chrysantha, O. pumila var. minima, O. pumila var. pusilla, O. pumila var. rectipilis, O. pusilla |
Name authority | L’Héritier ex Aiton: Hort. Kew. 2: 3. (1789) | Linnaeus: Syst. Nat. ed. 10, 2: 998. (1759) |
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