Oenothera humifusa |
Oenothera tetraptera |
|
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seabeach evening-primrose |
fourwing evening-primrose |
|
Habit | Herbs annual or short-lived perennial, densely strigillose, sometimes also villous, also becoming glandular puberulent distally. | Herbs annual or perennial, strigillose and also hirsute; from a slender taproot. |
Stems | erect to decumbent, much branched, 10–50(–90) cm. |
15–50 cm. |
Leaves | in a basal rosette and cauline, basal 4–8 × 0.7–1 cm, cauline 1–7 × 0.3–1.5 cm; blade usually grayish green, narrowly oblong to narrowly elliptic or narrowly obovate, margins remotely shallowly dentate to subentire; bracts spreading, flat. |
2.5–10 × 0.6–2.5 cm; petiole 0.2–2.2 cm; blade usually lanceolate to oblanceolate, sometimes elliptic, margins weakly serrate to sinuate-pinnatifid. |
Flowers | usually 1 opening per day near sunset; buds erect, with free tips erect and appressed or slightly spreading, 0.5–2 mm; floral tube 15–35 mm; sepals3–11 mm; petals yellow, very broadly obovate or obcordate, 4.5–16 mm; filaments 4–11 mm, anthers 2–5.5 mm, pollen ca. 50% fertile; style 23–45 mm, stigma surrounded by anthers at anthesis. |
1–3 opening per day near sunset; buds with free tips 0.5–3 mm; floral tube 10–30 mm; sepals 20–40 mm; petals white, fading pink, 20–43 mm; filaments 12–18 mm, anthers 5–10 mm, pollen 85–100% fertile; style 19–67 mm, stigma exserted beyond anthers at anthesis. |
Capsules | cylindrical, sometimes slightly enlarged toward apex, 15–45 × 2–3 mm. |
broadly clavate or obovoid, 20–51 × 5–7 mm, winged, wings 2–4 mm, valve surface with prominent midrib, proximal stipe 8–45 mm; sessile. |
Seeds | usually ellipsoid to broadly ellipsoid, rarely subglobose, 1–2 × 0.5–0.9 mm. |
narrowly obovoid, 1–1.5 × 0.5–0.7 mm. |
2n | = 14. |
= 14. |
Oenothera humifusa |
Oenothera tetraptera |
|
Phenology | Flowering Apr–Nov. | Flowering Feb–May. |
Habitat | Dunes, open sandy places along or near Atlantic coast. | Alluvial flats, open areas, sandy soil, weedy sites. |
Elevation | 0–10 m. (0–0 ft.) | 10–300[–2000] m. (0–1000[–6600] ft.) |
Distribution |
AL; DE; FL; GA; LA; MD; MS; NC; NJ; PA; SC; VA; Dunes; open sandy places along or near Atlantic coast; West Indies (Cuba); Bermuda
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TX; Mexico; Central America; West Indies (Jamaica); n South America [Introduced widely in temperate Europe, Asia, s Africa, Australia]
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Discussion | Oenothera humifusa is a PTH species and forms a ring of 14 chromosomes in meiosis, and is self-compatible and autogamous (W. Dietrich and W. L. Wagner 1988). The inland collection from Iredell County, North Carolina, presumably represents an introduction. There are two geographically separated morphological forms of O. humifusa. Plants of one form are somewhat decumbent, with subentire cauline leaves and bracts; this form occurs in the southern part of the range. The other form is more upright, with more deeply divided leaves; it occurs from North Carolina northward. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
In the flora area, Oenothera tetraptera is known only from southern Texas. Oenothera tetraptera presumably has become naturalized in South America (Argentina, Bolivia, Colombia, Ecuador, Venezuela), West Indies (Jamaica), Europe, Asia, South Africa, and Australia. Oenothera candida Dumont Courset is a superfluous name, as is O. candida Bellardi ex Colla, and they both pertain here. The name Hartmannia macrantha Spach is illegitimate and pertains here. (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. Raimannia | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Leucocoryne |
Sibling taxa | ||
Synonyms | O. niveifolia, O. sinuata var. humifusa, Raimannia humifusa | Hartmannia latiflora, H. tetraptera, O. latiflora, O. tetraptera var. immutabilis, Xylopleurum tetrapterum |
Name authority | Nuttall: Gen. N. Amer. Pl. 1: 245. (1818) | Cavanilles: Icon. 3: 40, plate 279. (1796) |
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