Oenothera pilosella |
Oenothera simulans |
|
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meadow evening-primrose |
southern beeblossom |
|
Habit | Herbs perennial, usually densely to sparsely hirsute, rarely glabrous; from a thickened base, rhizomatous. | Herbs annual, glabrate, strigillose, and/or hirtellous; from taproot. |
Stems | spreading or ascending, unbranched or few-branched distally, 20–80 cm. |
usually unbranched, sometimes several-branched from base, 60–180 cm. |
Leaves | in a basal rosette and cauline, basal 4–8 × 2–5 cm, petiole (0.5–)1–3(–4) cm, blade oblanceolate to ovate, margins entire; cauline 3–10(–13) × 1–2(–4) cm, petiole 0–0.5(–2) cm, blade lanceolate to ovate, abruptly narrowed to base, margins subentire or coarsely dentate. |
in a basal rosette and cauline, 0.8–13 × 0.1–1.6 cm; blade often red-blotched, narrowly lanceolate to narrowly oblanceolate, margins slightly to conspicuously sinuate-dentate. |
Inflorescences | erect, flowers in axils of distalmost few nodes. |
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Flowers | opening near sunrise; buds with free tips 1–3 mm, spreading; floral tube 10–25 mm; sepals 10–20 mm; petals bright yellow, fading pale pink or pale yellow, 15–30 mm; filaments 7–15 mm, anthers 4–8 mm, pollen 85–100% fertile; style 10–20 mm, stigma exserted beyond anthers at anthesis. |
3 or 4-merous, often mixed on a single plant, zygomorphic, opening near sunset; floral tube 3–8 mm; sepals 2.5–8 mm; petals white, fading pink, narrowly elliptic-obovate, 4.5–8 mm; filaments 2.5–6 mm, anthers 0.5–2 mm, pollen 90–100% fertile; style 7.5–19 mm, stigma surrounded by or slightly exserted beyond anthers. |
Capsules | usually oblong-clavate to oblong-ellipsoid or ellipsoid, 4-angled or weakly 4-winged, (5–)10–15(–28) × 2–4(–5) mm, stipe (1–)3–5(–9) mm; sessile. |
ellipsoid or ovoid, 3-(or 4-)angled, 5–9 × 2–3 mm; sessile. |
Seeds | 1 × 0.5 mm. |
2–4, yellowish to light brown, 1.2–2.3 × 0.8–1.1 mm. |
2n | = 56. |
= 14. |
Oenothera pilosella |
Oenothera simulans |
|
Phenology | Flowering May–Jul(–Aug). | Flowering (Feb–)May–Sep(–Nov). |
Habitat | Open fields, edge of woods, marshes and bottomland prairies, open disturbed sites, ditches, old fields, railroads, roadsides. | Sandy soil in open woodlands, fields, roadsides, primarily in outer Coastal Plain. |
Elevation | 100–600 m. (300–2000 ft.) | 0–10 m. (0–0 ft.) |
Distribution |
AL; AR; CT; IA; IL; IN; KY; LA; MA; ME; MI; MO; MS; NH; NY; OH; OK; PA; RI; VA; VT; WI; WV; ON
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FL; GA; NC; SC
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Discussion | Oenothera pilosella is widespread in cultivation in gardens and frequently escapes and becomes naturalized; the northern and eastern natural limits of O. pilosella are not clear. According to G. B. Straley (1977) the natural limits are from Wayne County, West Virginia, along the Ohio River and Erie County, New York, for the eastern limits, and Tuscola County, Michigan, and Manitowoc County, Wisconsin, for the northern limits. K. N. Krakos (2014), based on new field studies and phylogenetic data, found that O. pilosella does not form a monophyletic group with plants previously treated by Straley as O. pilosella subsp. sessilis in molecular analyses, and thus is here reinstated as the distinct species O. sessilis. Straley determined that O. pilosella is self-incompatible and an octoploid, one of the few in the genus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera simulans occurs along the Coastal Plain from Cape Hatteras, North Carolina, southward and throughout Florida. It is self-compatible and autogamous (P. H. Raven and D. P. Gregory 1972[1973]). The species occasionally persists through mild winters in the southern part of its range, appearing biennial. Gaura fruticosa Jacquin 1786, not G. fruticosa Loefling 1758, is an illegitimate later homonym that 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. Kneiffia | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Gaura > subsect. Gaura |
Sibling taxa | ||
Synonyms | Kneiffia fruticosa var. pilosella, K. pilosella, K. pratensis, K. sumstinei, O. fruticosa var. hirsuta, O. fruticosa var. pilosella, O. pratensis | Gaura simulans, G. angustifolia, G. angustifolia var. eatonii, G. angustifolia var. simulans, G. angustifolia var. strigosa, G. eatonii |
Name authority | Rafinesque: Ann. Nat. 1: 15. (1820) | (Small) W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 213. (2007) |
Web links |