Oenothera nutans |
Oenothera demareei |
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nodding evening-primrose |
demaree's beeblossom |
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Habit | Herbs biennial, often appearing glabrous to naked eye, usually strigillose and sparsely to moderately villous proximal to inflorescence, hairs translucent and with or without pustules, pustules not red (in fresh material), inflorescence glabrous, glandular puberulent, or strigillose and glandular puberulent. | Herbs usually robust winter-annual, sometimes biennial, densely strigillose throughout; from fleshy taproot. |
Stems | erect, red on proximal parts, green on distal ones, rarely red throughout, unbranched or with branches obliquely arising from rosette and secondary branches arising from main stem, 30–200 cm. |
usually well-branched distal to base, 50–400 cm. |
Leaves | in a basal rosette and cauline, basal 10–32 × 3–7 cm, cauline 6–20 × 2–8 cm; blade green to pale green, narrowly oblanceolate to narrowly obovate, or narrowly elliptic, sometimes lanceolate distally, margins usually flat, rarely undulate, bluntly dentate, teeth widely spaced, sometimes sinuate-dentate proximally; bracts caducous. |
in a basal rosette and cauline, 3–7 × 0.2–0.8 cm; blade narrowly elliptic to elliptic or lanceolate, margins subentire or shallowly undulate-denticulate. |
Inflorescences | erect, unbranched or with secondary branches just proximal to main one. |
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Flowers | opening near sunset; buds erect, 4–6 mm diam., with free tips terminal, erect, 1.5–6 mm; floral tube 30–43 mm; sepals yellowish green or flushed with red, 10–23 mm; petals yellow to pale yellow, fading pale yellowish white, very broadly obcordate, 14–25(–30) mm; filaments 10–25 mm, anthers 4–10 mm, pollen ca. 50% fertile; style 35–63 mm, stigma surrounded by anthers at anthesis. |
4-merous, zygomorphic, opening at sunrise; floral tube 4–13(–15) mm; sepals 13–20 mm; petals white, fading pink, rhombic-obovate, 10–17 mm; filaments 8–17 mm, anthers 3–7 mm, pollen 90–100% fertile; style 18–32 mm, stigma exserted beyond anthers at anthesis. |
Capsules | erect or slightly spreading, dull green when dry, narrowly lanceoloid to narrowly ovoid, 12–36 × 3–6 mm, free tips of valves 1–1.5 mm. |
ellipsoid or ovoid, sharply 4-angled, 4.5–7 × 1.5–2.5 mm; sessile. |
Seeds | 1–1.9 × 0.6–0.9 mm. |
2–4, yellowish to reddish brown, 1.2–3 × 0.7–1.3 mm. |
2n | = 14. |
= 14. |
Oenothera nutans |
Oenothera demareei |
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Phenology | Flowering Jun–Aug(–Sep). | Flowering Jul–Oct. |
Habitat | Open, often disturbed sites, stream beds, flood plains, slopes, margins of mixed deciduous forests, roadsides, old fields. | Open meadows in sandy loam. |
Elevation | (200–)400–1700 m. ((700–)1300–5600 ft.) | 70–200 m. (200–700 ft.) |
Distribution |
AL; AR; CT; DE; FL; GA; IN; KY; MA; MD; ME; MI; MO; NC; NH; NJ; NY; OH; PA; SC; TN; VA; VT; WV; ON |
AR |
Discussion | Oenothera nutans is a PTH species and forms a ring of 14 chromosomes or a ring of 12 and 1 bivalent in meiosis, and is self-compatible and autogamous (W. Dietrich et al. 1997). It has plastome III and a BB genome composition. The disjunct occurrences of O. nutans in Arkansas and Missouri probably represent unintentional introductions by humans. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera demareei is known only from Clark, Garland, Hempstead, Howard, Montgomery, Pike, Saline, and Sevier counties. P. H. Raven and D. P. Gregory (1972[1973]) found Oenothera demareei to be self-incompatible. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | O. austromontana, O. biennis subsp. austromontana, O. biennis var. austromontana, O. biennis var. nutans | Gaura demareei |
Name authority | G. F. Atkinson & Bartlett: Rhodora 15: 83. (1913) | (P. H. Raven & D. P. Gregory) W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 212. (2007) |
Web links |