Oenothera humifusa |
Oenothera grandiflora |
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seabeach evening-primrose |
large-flower evening-primrose |
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Habit | Herbs annual or short-lived perennial, densely strigillose, sometimes also villous, also becoming glandular puberulent distally. | Herbs biennial, often appearing glabrous to naked eye, usually sparsely to moderately strigillose and villous with pustulate, translucent hairs proximal to inflorescence, pustules not red (in fresh material), inflorescence glabrous, glandular puberulent, or strigillose and glandular puberulent. |
Stems | erect to decumbent, much branched, 10–50(–90) cm. |
erect, red on proximal parts, usually green on distal ones, rarely red throughout, unbranched or with branches obliquely arising from rosette and secondary branches arising from main stem, 100–300(–400) 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. |
in a basal rosette and cauline, basal 18–32 × (2–)3–6.5 cm, cauline 6–20 × 1.5–6.5 cm; blade soft and thin, bright green, usually flat, rarely undulate, narrowly oblanceolate to narrowly obovate, or narrowly elliptic to elliptic, sometimes narrowly ovate distally, margins bluntly dentate or subentire, teeth widely spaced, sometimes sinuate-dentate proximally or lobed; bracts usually caducous. |
Inflorescences | erect, often with secondary or tertiary branches just proximal to main one. |
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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. |
opening near sunset; buds erect, 5–9 mm diam., with free tips terminal, erect, 2–9 mm; floral tube 35–55 mm; sepals yellowish green or flushed with red, 22–46 mm; petals yellow to pale yellow, fading pale yellowish white, very broadly obcordate or obovate, (25–)30–45 mm; filaments 18–27 mm, anthers 10–15 mm, pollen 90–100% fertile; style 57–90 mm, stigma exserted beyond anthers at anthesis. |
Capsules | cylindrical, sometimes slightly enlarged toward apex, 15–45 × 2–3 mm. |
erect or slightly spreading, dull green when dry, narrowly lanceoloid to narrowly ovoid, 15–35 × 3.5–5.5 mm, free tips of valves 0.5–2.5 mm. |
Seeds | usually ellipsoid to broadly ellipsoid, rarely subglobose, 1–2 × 0.5–0.9 mm. |
1–1.7 × 0.6–1.2 mm. |
2n | = 14. |
= 14. |
Oenothera humifusa |
Oenothera grandiflora |
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Phenology | Flowering Apr–Nov. | Flowering Jul–Aug(–Sep). |
Habitat | Dunes, open sandy places along or near Atlantic coast. | Scattered, presumably relictual populations on chalky bluffs, loose sand over limestone, along streams, marshes, ditches, roadsides. |
Elevation | 0–10 m. (0–0 ft.) | 20–600 m. (100–2000 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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AL; FL; MS; NC; SC; TN |
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.) |
Oenothera grandiflora has a scattered distribution, from the eastern half of Mississippi and Alabama, east to Tennessee (Franklin and Marion counties), North Carolina (Cherokee, Macon, Martin, Moore, New Hanover, Sampson, and Swain counties), South Carolina (Oconee, Spartanburg, and Sumter counties), and Florida (Alachua, Escambia, Franklin, Lake, Leon, Polk, Putnam, and Santa Rosa counties). Collections from southern Canada, New York, Pennsylvania, Vermont, and West Virginia almost certainly represent cultivated plants, garden escapes, or adventive populations, and the single locality from central Kentucky also may be an introduction; it is sometimes a colonizer in disturbed sites such as along roads. Oenothera grandiflora has plastome III and a BB genome composition. As summarized by W. Dietrich et al. (1997), some populations of O. grandiflora seem to be entirely or mostly composed of self-incompatible individuals, whereas others consist of self-compatible plants. This is an extremely uncommon phenomenon within a single species of Oenothera; the only other species known to exhibit mixed populations of self-incompatible and self-compatible individuals is O. primiveris. Oenothera grandiflora Lamarck 1798, being a later homonym of O. grandiflora L’Héritier 1789, 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. Oenothera > subsect. Oenothera |
Sibling taxa | ||
Synonyms | O. niveifolia, O. sinuata var. humifusa, Raimannia humifusa | O. biennis var. grandiflora, O. grandiflora var. glabra, O. grandiflora var. pubescens, O. lamarckiana, O. spectabilis |
Name authority | Nuttall: Gen. N. Amer. Pl. 1: 245. (1818) | L’Héritier in W. Aiton: Hort. Kew. 2: 2. (1789) |
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