Oenothera parviflora |
Oenothera engelmannii |
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northern evening-primrose, small-flower evening-primrose |
Engelmann's evening-primrose |
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Habit | Herbs biennial, sparsely strigillose, glandular puberulent, and villous with pustulate or non-pustulate hairs, sometimes predominately strigillose proximally or predominately villous with pustulate or non-pustulate hairs distally, glabrous, or some mixture of strigillose, glandular puberulent, or sparsely villous distally, sometimes appearing glabrous to the naked eye. | Herbs winter-annual, conspicuously villous throughout, also strigillose on leaves and distal parts; from a taproot. |
Stems | erect, green or red on proximal parts or throughout, mostly branched from base or only in distal 1/2, 30–150 cm. |
erect, unbranched or with few, spreading branches, 30–50(–80) cm. |
Leaves | in a basal rosette and cauline, basal 10–30 × 1–4 cm, cauline 4–18 × 1–3 cm; blade usually bright green, sometimes pale green distally, white- or red-veined, narrowly oblanceolate, narrowly elliptic to lanceolate, or oblong, margins usually flat, rarely undulate, regularly dentate to remotely denticulate, sometimes teeth widely spaced; bracts persistent. |
in a basal rosette and cauline, rosette weakly developed or absent, at least during flowering, (1–)2–6(–8) × 1–2(–3) cm; sessile; blade lanceolate to oblong lanceolate, proximal ones sometimes oblanceolate, margins coarsely repand-dentate or -pinnatifid. |
Inflorescences | erect or ± curved, unbranched or with secondary branches just proximal to main one. |
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Flowers | opening near sunset; buds erect, 3–5 mm diam., with free tips subterminal, spreading to erect, 0.5–5 mm; floral tube 22–40 mm; sepals green to yellowish green or flushed with red or dark red, sometimes only red-flecked, 7–17 mm; petals yellow to pale yellow, fading pale yellow to pale yellowish orange, very broadly obcordate, 8–15(–20) mm; filaments 7–13 mm, anthers 3.5–6 mm, pollen ca. 50% fertile; style 25–50 mm, stigma surrounded by anthers at anthesis. |
1–several opening per day near sunset; buds nodding, weakly quadrangular, without free tips; floral tube 20–30 mm; sepals 13–21 mm, not spotted or with scattered small, maroon spots; petals white, fading pink, broadly obovate or obcordate, 15–30 mm; filaments 14–16 mm, anthers 6–8 mm; style 40–50 mm, stigma exserted beyond anthers at anthesis. |
Capsules | erect or slightly spreading, usually greenish black when dry, narrowly lanceoloid to lanceoloid, 20–40 ×3.5–5 mm, free tips of valves 1–1.5 mm. |
widely spreading, woody in age, straight or slightly curved, cylindrical, obtusely 4-angled, especially toward base, tapering gradually from base to apex, 30–60 × 2–3 mm; sessile. |
Seeds | 1.1–1.8 × 0.5–1 mm. |
numerous, in 1 row per locule, brown, narrowly obovoid, 1–1.5 mm. |
2n | = 14. |
= 14. |
Oenothera parviflora |
Oenothera engelmannii |
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Phenology | Flowering Jun–Aug. | Flowering Apr–Aug(–Sep). |
Habitat | Open or disturbed, sandy or gravelly sites, roadsides, fallow fields, clearings, riverbanks, along water courses, salt marshes, coastal meadows. | Sandy prairies, dunes, disturbed areas, roadsides. |
Elevation | 0–1700 m. (0–5600 ft.) | 500–1300 m. (1600–4300 ft.) |
Distribution |
CT; DC; DE; IA; IL; IN; KY; MA; MD; ME; MI; MN; MO; NC; ND; NH; NJ; NY; OH; PA; RI; TN; VA; VT; WI; WV; BC; NB; NF; NS; ON; PE; QC [Introduced in Europe, Asia (ne China, Japan), s Africa, Pacific Islands (New Zealand), Australia]
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CO; KS; NM; OK; TX
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Discussion | Oenothera parviflora is a PTH species and forms a ring of 14 chromosomes in meiosis, and is self-compatible and autogamous (W. Dietrich et al. 1997). It has plastome IV and a BC genome composition. Onagra chrysantha Spach 1835, not Michaux 1803, is a superfluous name, as is Onagra chrysantha var. parviflora (Linnaeus) Spach, and both pertain here. O. biformiflora var. cruciata R. R. Gates is an invalid name that pertains here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera engelmannii is self-incompatible (W. L. Wagner et al. 2007; K. E. Theiss et al. 2010). It has a relatively narrow distribution in sandy areas of eastern New Mexico and western Texas, extending to southeastern Colorado, western Oklahoma, and southwestern Kansas. The flower size seems to vary, with larger flowers in eastern New Mexico and considerably smaller flowers in the eastern part of its range. (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. Oenothera > subsect. Oenothera | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Anogra |
Sibling taxa | ||
Synonyms | O. ammophiloidesr. var. flecticaulis, O. ammophiloides var. parva, O. angustifolia, O. angustissima, O. angustissima var. quebecensis, O. apicaborta, O. atrovirens, O. biennis var. cruciata, O. biennis var. parviflora, O. biformiflora, O. cleistantha, O. comosa, O. cruciata, O. cruciata var. sabulonensis, O. deflexa, O. flecticaulis, O. hazeliae, O. hazeliae var. parviflora, O. hazeliae var. subterminalis, O. intermedia, O. laevigata, O. laevigata var. scitula, O. laevigata var. similis, O. novae-scotiae, O. novae-scotiae var. distantifolia, O. novae-scotiae var. intermedia, O. parva, O. parviflora subsp. angustissima, O. parviflora var. angustissima, O. robinsonii, O. rubricapitata, O. scitula, O. subterminalis, O. venosa, Onagra biennis var. cruciata, O. chrysantha var. cruciata, O. cruciata, O. parviflora | Anogra pallida var. engelmannii, A. engelmannii |
Name authority | Linnaeus: Syst. Nat. ed. 10, 2: 998. (1759) — (as parviflor) | (Small) Munz: Amer. J. Bot. 18: 316. (1931) — (as engelmanni) |
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